WO2024065340A1

WO2024065340A1 - Harmonic-structured hydraulic binder, manufacturing method thereof and strength-decoupled high elastic modulus cementitious composite material made using the same.

Info

Publication number: WO2024065340A1
Application number: PCT/CN2022/122356
Authority: WO
Inventors: Chi Kuen WONG; Yee Sun Calvin YAU
Original assignee: Flexcrete Technology Limited
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2024-04-04

Abstract

A novel strength-decoupled high elastic modulus cementitious composite (10), and a novel harmonic-structured hydraulic binder compositions (11). The compositions (11) comprise an effective amount of bimodal coarse (21) and ultrafine hydraulic particles (27) forming core-shell self-assembled clusters matrix. The cementitious composite (10) elements show substantial improved elastic modulus and durability material properties, particularly towards structural deformation and sustainability.

Description

HARMONIC-STRUCTURED HYDRAULIC BINDER, MANUFACTURING METHOD THEREOF AND STRENGTH-DECOUPLED HIGH ELASTIC MODULUS CEMENTITIOUS COMPOSITE MATERIAL MADE USING THE SAME.

FIELD OF THE INVENTION

This invention relates broadly to an innovative form of cementitious composite material system having a new core-shell harmonic-structured hydraulic binder matrix which gives an outstanding strength-decoupled elastic modulus mechanical property in comparing with the current state of art ultra-high performance cementitious composite (UHPC) materials approach. As opposed to the UHPC approach in achieving high elastic modulus by adopting extremely low water/cementitious binder-filler ratio together with special reactive type aggregate, this invention of Strength-decoupled high elastic modulus cementitious composite utilizes with the Core-Shell harmonic-structured design of continuous three-dimensional network which constitutes a high bond density epitaxial growing hydraulic cementitious binder gel layer microstructure and yet it is fundamentally different from that of normal cementitious binder gel. This enhanced behaviour is essentially related to the magic of synergy effects of using organic structure-directing agent as an essential step to tailor-made the core-shell harmonic-structured hydraulic cementitious binder clusters. As will become apparent, this invention provides the realization of low carbon footprint high elastic modulus modest strength cementitious composite through an energy efficient shear-friction based attrition process of manufacturing the ultrafine grain direct acting hydraulic cementitious material from abrasive blast furnace slag in lieu of the state of art low yield air-classify production route. From a material engineering point of view, the focus of this invention is to advance a holistic approach to the design and manufacturing of novel cementitious composite materials that meet the challenges of sustainable development of the construction industry.

Prior Art Cementitious Composite Technologies

Construction materials provide the essential fabric for modern civilization; they must be cheap and readily available. Cementitious composite like concrete is the dominance construction material facing a wide range of challenges today such as fast construction cycle and high performance requirements, many of which are linked to the need for sustainable development, reducing the consumption of raw materials, reducing energy used in processing, and increasing service life.

As shown in FIG. 1a and 1b, the modulus of elasticity of concrete is required for the analysis on the deformation of buildings and civil structures under dynamic loads particular the wind and earthquake loads. It is also used for determining the modular ratio, m. Modulus of elasticity is dependent on the compressive strength of concrete, properties of the coarse aggregates, the proportion of the aggregates in the concrete and addition of mineral admixtures. Specifying the largest practical maximum size of aggregate and a suitable concrete grading may result in higher content of coarse aggregate in a concrete mixture. Such concretes tend to have a higher modulus of elasticity, provided that the aggregate used have a high modulus of elasticity. However, increasing the coarse aggregate size may result in reduced strength in high-strength concrete mixtures due to the cement paste failure in binding with the coarse aggregate.

Increasing the paste content and decreasing the water-cement ratio will increase the modulus of elasticity and therefore Ultra-high performance Concrete (UHPC) Composite Technologies having both very high compressive strength and higher modulus of elasticity are well-known art of this kind in construction industry. For example, to increase the modulus of elasticity by 20%it may be necessary to increase the compressive strength by 50%. High strength with high elastic modulus concrete is often used in columns, shear walls of high-rise buildings long-span bridges, parking garages and offshore structures, where properties of improved density, lower permeability, and increased resistance to freeze-thaw and corrosion are required. In these applications, designers can take full advantage of the increased compressive strength and modulus of elasticity to reduce the amount of steel, to reduce structure member size (to increase usable floor space in high-rise buildings) , or to have additional stories built.

With reference to FIG. 2a and 2b a typical elastic modulus of concrete related to compressive strength of concrete given by various structure design codes which are used by designer for structural engineering stability checking. The elastic modulus for concrete with 60 MPa compressive strength is around 30GPa～32GPa at 28 days by using the most commonly available granite aggregate. With reference to FIG. 3a and 3b modulus of elasticity of concrete with different types of aggregate related to the compressive strength of concrete are shown. The elastic modulus for concrete with 60 MPa compressive strength by using reactive aggregate such as basalt is around 45GPa～47GPa at 28 days. However reactive aggregate may led to alkaline silica reaction problem in hardened concrete and design codes stipulate special treatment method to control this issue.

Pressure on the concrete industry to reduce construction schedules has led to subjecting concrete members to load long before the conventional 28-days curing period has been completed. Adequate knowledge of the compressive strength, modulus of elasticity, splitting tensile strength and Poisson’s ratio are necessary for safe formwork stripping and early load applications. With reference to FIG. 3c a typical rate of development of physical properties of concrete at early ages is shown, the result shows that elastic modulus developed much faster than either the tensile or the compressive strength, which developed at approximately the same rate. The period within the first 12 hr after casting was observed to be the period of fastest development of physical properties. In particular, the static elastic modulus is the most important characteristic of concrete. It is a basic parameter necessary for estimating prestress losses, predicting early-age buckling loads of long columns.

In construction industry the technology based on using fibre reinforced ultra-high performance concrete as shown in FIG. 4a is generally named UHPC and its best known high performance products are Ductal and Dura. However the main application of Ductal and Dura is in the precast industry and yet the Portland cement content are more than 700kg for one cubic meter concrete to achieve 45GPa modulus of elasticity with 150MPa compressive strength. In FIG. 4b similar aggregate types effect on the change of elastic modulus value in UHPC composites are observed again as in ordinary strength concrete.

It is also known that state of the art manufacturing of ultrafine slag is limited to the low yield air-classification method with very low yield. With reference to FIG. 5a and 5b a typical two stage production route using impact-based vertical roller grinding method is proposed for slag grinding up to 15 micron particle size and the small fraction ultrafine particle can only be extracted by multi-cyclone air-classifier. To replace Portland cement clinker with latently hydraulic granulated blast furnace slag (GGBS) in substantial amounts, processing of GGBS to a fineness of less than ‘5’ microns in particle size should be the aim for activation of GGBS to form a direct acting hydraulic binder. However, the process technologies currently in use fail to reach that aim due to economic reasons.

Thus, there is still a definite need in the art for modest strength high modulus of elasticity cementitious composite materials that can be utilized for structural application and fulfilling current performance requirement of design code, while at the same time eliminating all the above mentioned hitherto known limitations such as high cost, limited production volume, high brittleness because of ultrahigh strength, slow hydration rate, with an innovative low carbon content active robust cementitious composite material design and manufacturing approach ready for mass adoption.

Key Problems in Current High Performance Cementitious Composite Material Development

Deflection is an important serviceability limit state to be satisfied in the design of architectural and civil engineering structures, such as tall buildings, bridges, etc., that generally employs reinforced concrete. Conventionally, designers have to use large cross-section area for beams and columns to control structural deformation, as the stiffness of the structure is much more critical than strength for tall buildings and bridges. There is no doubt that enhancing the modulus of elasticity of concrete itself is much more efficient than increasing the structural members sizing in respect to sustainability requirements.

Established design specifications and concrete codes regarding strength-coupled elastic modulus practice have been published and widely applied to cater for higher performance of the reinforced concrete structure such as Ultra High Performance Fibre Concrete with 150MPa strength for 45GPa elastic modulus. From the perspective of environmental and economic benefit, development of modest strength high elastic modulus concrete can save construction materials and also increase usable area inside tall buildings.

Concrete is a composed of granular material (i.e. aggregate or filler) embedded in a hydrated matrix gel of cementitious material (i.e. cement and/or other binders) that fills the space between the aggregate particles and glues them together. Bond strength and microstructure structural properties of cementitious hydrated gel vary with the volume of space to be filled and mechanism of hydration.

Current state of the art high performance cementitious composite materials are limited by adjusting the components inside the concrete or the proportions among them and the incorporation of pozzolanic by-products or mineral admixture without enhancing the intrinsic strength of cementitious matrix by increasing the total number of effective chemical bonds per unit area of the matrix material. In contrast to conventional cementitious matrix processing, the present invention is focused on new processing strategies and techniques for controlling microstructure of cementitious hydrate crystal growth and realization of the novel concept of “strength-decoupled high elastic modulus cementitious composite materials” .

Key Problems in Current Production of Direct Acting Hydraulic Binder from Ground Granulated Blast Furnace Slag

Ground granulated blast furnace slag (GGBS) is a glassy granular material essentially consisting of silicates and aluminosilicates of calcium and other oxides. Blast furnace slag has latent hydraulic activity characteristic, i.e. it develops cementitious properties when exposed to water with very slow process of hydration is very slow due to the formation of an impervious aluminosilicate film on the surface. Poor reactivity of slag restricts its utilisation in Portland Slag cement and any other application where the reactivity of the slag is of importance. In the existing application process, the blast furnace slag does not actively participate in the early age hydration reaction; as a result of the large particle size effect it hydrates very slowly and incompletely. Indeed, the GGBS material staying most active on the hydraulic reactivity in the cementitious binder systems usually has the size of about ‘1’ - ‘5’ microns and fineness of about 7000-10,000 cm2/g.

Attrition mills are now widely used for grinding solids down to the sub-sieve size range, finer than 10 micron or so for instance. The process of mechanical activation of blast furnace slag however ends up with destabilisation of impervious aluminosilicate surface film as per mill specific. In the other words, it depends on milling mechanism and mill dynamics. Thus, the problem of providing an energy efficient attrition mill type for ultrafine blast furnace slag mass production still remains unsolved.

Advancement in microstructure design for high-performance metallic materials

Very interestingly, ultrafine-grained and heterostructured materials have been drawing great attention to the materials research community because of their superior mechanical and functional properties. With reference to FIG. 6b creation of harmonic-structure in metals and alloys is a new material design paradigm allowing the enhancement of strength-ductility structural performance. By using mechanical milling such as jet milling to obtain bimodal “harmonic” structure in the metal powders followed by spark plasma sintering process, a three-dimensional network of equiaxed ultrafine grain shell enclosing the coarse grain core areas are formed to create an innovative structural metallic materials with specific microstructure for promoting uniform distribution of strain during plastic deformation and for avoiding the localized plastic deformation in the early stages of deformation. The benefits of “harmonic” structure observed in the applicability of this microstructural design can be extended to a wide range of metallic materials, irrespective of the nature of material, phase, or crystal structure.

However, this prior art practice contains no suggestion to combine this or a similar principle for adoption in any type of cementitious material. The concept of a 3-dimensional arrangement of harmonic-structured hydrate gel microstructure is in no way suggested by any research communities for the simple reason that such an intricate arrangement of cementitious matrix binder would have been regarded by a person skilled in the art as involving an unnecessary expenses and difficulties without any expectation of technical benefit. Thus, the problem of providing cementitious composite material matrix with improved organized network structure remains unsolved.

Harmonic-Structured microstructure control for high elastic modulus hydraulic binder materials

It is a main object of the present invention providing novel cementitious composite materials with improved performance characteristics, in particular under static and dynamic deformation conditions. One aspect of the present invention represents a further development of construction material with harmonic-structured microstructure mentioned above, enabling the production of cementitious composite materials that are extremely deformation resisting under both static and dynamic conditions, and which also show strength-decoupled characteristic.

Novel cementitious composite materials according to the invention are unique in showing high deformation resistance in all three directions as well as the capability of establishing the best methodology of incorporating ground granulated blast furnace slag in cementitious matrix phase in order to capitalise on its ability to contribute to modulus of elasticity and durability. The method of incorporating slag of ultrafine fineness into the formation of three-dimensional cementitious hydrate gel network has an important bearing on the novel strength-decoupled high elastic modulus cementitious composite materials development of the present invention. It demands innovation in the ultrafine grinding of hydraulic binder materials, template based processing of bimodal cluster and low water ratio proportioning of mixture phases to obtain the Harmonic-Structured microstructure control in matrix gel. All these features play an essential role in the formation of generating continuously connected network hydrate gel from the bimodal core-shell cluster.

More elaborations about these new features and advantages are presented now immediately below in the respective summary descriptions as well as later on in the detailed description of the invention.

SUMMARY DESCRIPTIONS OF THE INVENTION

Strength-Decoupled High Elastic Modulus Cementitious Composite Materials

From a systemic perspective, the invention may be described as a heterogeneous binary cementitious binder composite material system which can be characterized in (a) an unique harmonic-structured direct acting hydraulic cementitious matrix binder phase, (b) a latent hydraulic-pozzolanic cementitious matrix filler phase, (c) coarse-to-fine aggregate skeleton inclusion phase, and (d) soft organic dispersing agent based on the composite rule of mixture proportioned under low water/cementitious binder-filler ratio.

The present invention, in addition to the systemic perspective of the above, further propose a new bimodal core-shell cluster packing mechanism of “Coarse Grain Core (CGC) ” – “Ultrafine Grain Shell (UGS) ” particles for continuous connected network hydrate gel generation in lieu of traditional random cementitious matrix arrangement.

Another feature of the present invention is to provide a novel ultrafine dry attrition milling method of making ultrafine grain shell hydraulic cementitious material by activation of latently hydraulic finely ground granulated blast furnace slag to form a direct acting hydraulic cementitious binder.

Organic Structure-Directing Agent Modulate Prenucleation Bimodal Core-Shell Clusters

It is a known fact that ultrafine ground granulated blast furnace slag with particle size below ‘10’ microns will become negatively charged on its material surface. According to a preferred and best-mode embodiment of the invention, what is proposed, from a hydration-formed crystalline, processing strategy point of view, is using organic polycation addition as, (a) ultrafine slag bridging-stabilization dispersing agent, (b) bimodal core-shell sub-unit topology structure directing agents and (c) fluidity promoting agents in association with anionic comb polymer dispersing agents.

Epitaxial Growth For Hydrate Gel Morphology Control

The present invention, as mentioned above, also proposes confinement based morphological transformation control to promote formation of continuous epitaxial layer hydrated gel products overlaid on the coarse grain core surface. According to a preferred and best-mode embodiment of the invention, what is proposed, from a space confinement, processing strategy point of view, is using (a) low water/cementitious binder-filler ratio as gel-space packing control, (b) bimodal core-shell as optimized binder packing and (c) higher powder-aggregate ratio in skeleton inclusion phase.

Apparatus for Implementing Novel Attrition Grinding Activation

The present invention, as mentioned above, also proposes special apparatus for carrying out the mechanical activation processing of reactive blast furnace slag. According to a preferred and best-mode embodiment of the invention, what is proposed, from a shear-friction based attrition, processing strategy point of view, is using (a) dry horizontal technology to eliminate gravity effect, (b) special planar spiral expanded agitator elements as friction-shear based ultrafine milling process and (c) special organic polymer as comminution agglomeration inhibiting agents and surface activation agents.

These and various other features and advantages of, and offered, the present invention will become more fully apparent as the detailed description of it below is read in conjunction with the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

(Figure. 1a) Prior art showing typical concrete strength-elastic modulus requirement in tall building design.

(Figure. 1b) Prior art showing typical concrete strength-elastic modulus linear relationship up to 45GPa.

(Figures. 2a&b) Prior art showing typical concrete strength-elastic modulus coupling relationship in regulation and code.

(Figures. 3a&b) Prior art showing typical aggregate type-elastic modulus coupling relationship in regulation and code.

(Figure. 3c) Diagram showing rates of development of physical properties of concrete at early ages and types of binder materials.

(Figure. 4a) Prior art showing ultra high performance fibre concrete elastic modulus value in commercial products.

(Figure. 4b) Pior art showing aggregate effect on ultra high performance fibre concrete elastic modulus value.

(Figures. 5a&5b) Prior art showing air-classification ultrafine ground granulated blast furnace slag process.

(Figure. 6a) Prior art showing typical cementitious material and random arranged cementitious matrix phase.

(Figure. 6b) Prior art showing harmonic-structured metal alloy microstructure design.

(Figure. 7a) Diagram showing strength-decoupled high elastic modulus cementitious composite material range in articles of the invention.

(Figure. 7b) Diagram showing strength-decoupled high elastic modulus cementitious composite material range in comparison with code based range.

(Figure. 7c) Diagram showing unique harmonic-structured cementitious matrix phase in articles of the invention.

(Figure. 7d) Diagram showing unique bimodal Coarse Grain Core-Ultrafine Grain Shell packing and topochemical hydration process in articles of the invention.

(Figure. 8a) Diagram showing unique harmonic-structured high elastic modulus cementitious binder matrix hydration process in articles of the invention.

(Figure. 8b) Diagram showing shifting on rate of elastic modulus development under different water-cementitious binder (direct hydraulic binder) ratio in articles of the invention.

(Figure. 8c) Diagram showing unique harmonic-structured high elastic modulus cementitious composite overall processing in articles of the invention.

(Figure. 9) Diagram showing unique harmonic-structured high elastic modulus cementitious composite overall rule of mixture proportioning process in articles of the invention.

(Figure. 10) Diagram showing unique organic structure-directing agent and organic dispersing agent effect with core-shell particles.

(Figure. 11) Diagram showing unique planar spiral expanded agitator element and agitator shaft in articles of the invention.

(Figure. 12a) Diagram showing unique grinding test with organic agent in the articles of the invention.

(Figure. 12b) Diagram showing unique low energy grinding test result in the articles of the invention.

(Figure. 13a) Example showing proposed cementitious composite mixture ratio in articles of the invention.

(Figure. 13b) Test results for example cementitious composite mixture ratio in articles of the invention.

(Figure. 13c) Robustness examples showing proposed cementitious composite mixture ratio in articles of the invention.

(Figure. 13d) Test results for robustness example cementitious composite mixture ratio in articles of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Turing now to the drawings, and referring first of all to FIG. 7a, 7b and 7c inclusive, indicated generally at the novel strength-decoupled high elastic modulus cementitious composite material (10) is a multiphase composite material based on the said composite mixing rule of constructed in accordance with a preferred and best-mode embodiment of the present invention. Preferred multiphase composite material is inclusive of (a) direct acting hydraulic cementitious matrix binder phase, (b) latent hydraulic-pozzolanic cementitious matrix filler phase, (c) coarse-to-fine powder-aggregate skeleton inclusion phase, (c) water and organic structure-directing functionalizing agents, (d) soft organic dispersing agents and optional (e) organic-metallic fibre reinforcement phase. The direct acting hydraulic cementitious matrix phase is an unique harmonic-structured cementitious matrix of bimodal core-shell cluster (20) which has a heterogeneous binary hydraulic binder composition compose of direct acting hydraulic cementitious binder materials. The novel strength-decoupled high elastic modulus cementitious composite material (10) is characterized by an organized 3D network structure of continuously connected compact form cementitious hydrate gel layer (30) of the said Ultrafine Grain Shell (UGS) particles (27) encapsulating unhydrated Coarse Grain Core (CGC) particles (21) forming bimodal core-shell cluster. The novel composite material shows a unique microstructure array which has a tremendous performance on deformation bearing. This bimodal core-shell cluster (20) with high bond density between the particles surges an interlocked strain distribution action and which becomes a key feature of the strength-decoupled high elastic modulus cementitious composite material (10) of the present invention.

A common direct acting hydraulic cementitious binder material is Portland cement clinker grinded with particle size above ‘20’ microns. In lieu of ultrafine Portland cement, ultrafine ground granulated blast furnace slag is another direct acting hydraulic cementitious material and its selection guidelines are based on the reaction rate and silicate composition consideration. The excessively fast dissolution rate of ultrafine Portland cement however is unsuitable for the making of such stable bimodal core-shell cluster arrangement and that is another main feature of the present invention. As shown in FIG. 7d the heterogeneous binary hydraulic binder with specific spatial topology arrangement of bimodal core-shell cluster (20) includes Coarse Grain Core particles (21) composed of positively surface charged Portland cement grain and Ultrafine Grain Shell particles (27) composed of negatively surface charged direct acting hydraulic binder material of ground granulated blast furnace slag. The mediation process (40) controls both the nucleation and growth of cementitious hydrate morphology and the development of organized 3D network structured cement hydrate gel layer (30) .

Now turning to the proposed novel hydration transformation process as shown in FIG. 8a, 8b and 8c the bimodal Core-Shell cluster (20) plays an essential role in developing favourable bonding characteristics at the Coarse Grain Core particles sphere interfaces and in promoting the epitaxial growing based hydration of the direct acting hydraulic cementitious binder matrix. Bonding is associated with the formation of an intermediate layer of aluminium-rich calcium silicate hydrate, produced by an interfacial reaction of the Coarse Grain Core particles (21) with the epitaxy Ultrafine Grain Shell particles (27) under confined spatial morphology environment (32) at low water-cementitious binder-filler ratio (41) . This confinement based dissolution significantly promotes the precipitation of epitaxial C-S-H and C-A-S-H gel formations, which are produced by the topochemical reactions between silicate ions and the dissociated Si and Al with the abundant Ca ions released from the calcium hydroxide. With increased hydration, the bimodal core-shell cluster (20) are overlapped by each other with epitaxy hydration phenomenon forming cementitious hydrate gel layer slab (31) . While the epitaxy is in vicinity of the Coarse Grain Core particles surface, the unreactive Calcium Hydroxide also precipitates in the cementitious hydrate gel (31) formed at the interfacial regions between the Coarse Grain Core particles (21) and the ultrafine grain shell transformed reaction products developed in the organized 3D network structured cement hydrate gel layer (30) . However, the deposited calcium hydroxide is masked entirely within the hydrated reaction product layers. Finally, a dense continuous connected cementitious hydrate gel (31) consisting of a rim structure of approximately ‘4’ ～’10’ microns thickness acts in cross-linking and coupling functions that serve to connect and encapsulate the Coarse Grain Core particles (21) matrix. This direct morphological transformation hydration gel growth process (40) which occurred on the Coarse Grain Core particles (21) surface develops the typical geometrically reticulated network structure of the lath-like cementitious hydrate gel (31) associated with an assembly of hybrid C-A-S-H and C-S-H phases of the Ultrafine Grain Shell particles (27) structure and thereby the elastic modulus decoupling characteristic structure of the proposed invention is revealed.

With reference to FIG. 8b, the low water-cementitious hydraulic binder ratio (41) is effectively shifting the elastic modulus developing rate from the 6 to 12 hr critical period at the early stage hydration to the 0 to 6 hr critical period coincided with the vigorous direct hydration reaction requirement of the Ultrafine Grain Shell particles (27) .

As illustrated in FIG. 9, the novel strength-decoupled high elastic modulus cementitious composite materials (10) manufactured by the grinding and setting reaction process (60) according to the present invention may be manufactured qualitatively with much lower Portland cement content, which means that carbon dioxide emissions will be significantly reduced and further elastic modulus enhancement can be realized by adding 5%～10%ultrafine zeolite powder (61) as catalyst agent.

Looking specifically at FIG. 10, the organic structure-directing agent (80) is a polycationic compound bearing quaternary ammonium group and strategically adopted as bridging agent to wrap around the negatively charged ultrafine ground granulated blast furnace slag hydraulic binder particles. This bridging mechanism drives the formation of core-shell bimodal cluster subunits and thereby fabricates the continuous connected network hydrate gel with the activities of: (a) confining topochemical reaction within the shell layer; (b) producing compact and high modulus C-S-H/C-A-S-H crystalline hydrate with long range order; and (c) packing together bimodal cluster subunits together in a moving front self-assembly process to form fully densified macroscopic structures.

In principle, any material microstructure with network configuration and improved bond density for strain resistance will also increase its resistance in bending and enhances its elastic modulus mechanical property. Therefore, a quantum jump in the modulus of elasticity of the cementitious hydrate gel microstructure (31) can be realized by providing elaborate bimodal Core-Shell cluster subunits (20) duplicated by the template functioning of organic structure-directing agent (80) in a substantially homogenous and three-dimensional packing arrangement (32) .

Especially interesting to this quantum jumping deformation resistance capacity of the present invention is that such changes in elastic modulus capability may be achieved without in any alterations to the coarse-to-fine aggregate skeleton inclusion phase by reactive type aggregate composition within the novel harmonic-structured cementitious matrix. In other words, this invention provides a striking strain distribution counter-balance action between cementitious matrix binder phase and aggregate phase.

According to literature and patent survey and available information, it may be mentioned that at present no mass production process with high efficiency is available to produce reactive ultrafine blast furnace slag by dry mechanical activation and that refers to the grinding particle size of below ‘10’ microns together with surface change (s) induced in the solid phase by shear-friction attrition process. Complete hydration of the blast furnace slag without any chemical addition is not possible with any of the hitherto known process. Looking specifically at FIG. 11, the horizontal dry agitator (90) is a shear-friction based ultrafine blast furnace slag agitator grinder designated by: (a) planar spiral expanded agitator element (91) transversely arranged with predetermined spacing on a horizontal rotating shaft (93) ; (b) radially outermost ends of the agitator elements being spaced from the internal surface of grinding container (92) and (c) outer ends of the agitator elements positioned to trace a helix in the grinding container (92) . This developed ultrafine dry grinding equipment may be described as medium-kinetic horizontal-rotary-ball-mill.

A major advantage of dry grinding in an agitated media mill is that the treated material remains dry while it is ground in the mill and requires no moisture removal after grinding. And thus, it reduces the production cost drastically by eliminating the high energy consuming drying equipment. Due to the fact that ultrafine particles show strong reagglomerating behaviour when the particle size is smaller than ‘5’ microns, organic alkanol amine type surface-active grinding aid substances (94) are indispensable for a successful and scalable mechanical activation process.

Referring to FIG. 12a and 12b, “DEIPA” N, N-bis (2-hydroxyethyl) -2-propanolamine as organic surface-active grinding aid substances (94) give evidence of an unexpected enhanced grinding performance as ultrafine blast furnace slag grinding aid additives in comparison with Glycol. It is observed that the grinding of using DEIPA can be mostly described as, in terms of grinding efficiency, less energy consumption to produce uniform fineness (Blaine) per grinding aid agent dosage.

The invention will be further illustrated in the following non-limiting examples.

Example 1

Describing now the composition of novel strength-decoupled high elastic modulus cementitious composite material” (10) , and looking at the overall composition as shown in FIG. 13a, it includes bimodal core-shell hydraulic cementitious binder phase (11) with heterogeneous binary direct acting hydraulic cementitious materials: “Coarse Grain Core particles (21) –Portland Cement particles” and “Ultrafine Grain Shell particles (27) –ultrafine ground granulated blast furnace slag particles” as direct acting hydraulic reactive-based binder matrix phase; latent hydraulic cementitious filler matrix phase (23) ; coarse-to-fine aggregate skeleton inclusion phase (24) : Fine Powder Aggregate and Coarse Aggregate; soft organic dispersing agent (25) and fresh water (26) .

For industrial applicability consideration particularly fitting into ready mix concrete plant adoption, the proposed coarse-to-fine aggregate skeleton inclusion phase shall preferably be limited to common type mineral rock such as crushed granite stone fine and crushed granite coarse aggregate.

The cementitious material composition shown in FIG. 13a may take on a particular compositional mix based on the materials of bimodal core-shell hydraulic cementitious binder (11) including Ordinary portland cement (OPC) and Ultra-fine ground granulated blast furnace slag (UFGGBS) , Latent ground granulated blast furnace slag (GGBS) cementitious matrix filler phase, associated with soft organic structure-directing agent (80) , granite powder and aggregate skeleton inclusion phase (24) , soft organic dispersing agent (25) with phosphonate based organic comb polymer and fresh water (26) .

Table-1 below shows the constituents of the cementitious matrix phase of Example1 for the manufacturing of the “novel strength-decoupled high elastic modulus cementitious composite materials (10) ” containing a hydraulic binder phase with bimodal core-shell clusters (20) of a Coarse Grain Core particles (21) and Ultrafine Grain Shell particles (27) which are determined by weight standard.

The test result after 28 days normal curing are shown in FIG. 13b HOKALS test result table. It clearly demonstrate the high quality deliberation of core-shell continuous network connected hydrate gel layers interface strengthening strategy and which realizes the strength-decoupling high elastic modulus cementitious composite materials development without employing ultra high strength concrete design approach and/or reactive hard aggregate inclusion approach.

Example 2

In a further step, the cementitious material composition and test result shown in FIG. 13c and 13d may take on a variation of the powder-aggregate ratio and water-cementitious binder-filler ratio to demonstrate the robustness of the proposed harmonious-structured cementitious binder matrix approach.

Apart from a change of the granulated blast furnace slag grain sizes the proposed novel dry grinding process also has an effect particularly on a direct topochemical hydraulic reaction between the starting materials, which resulted in the inventive harmonious-structured cementitious binder matrix microstructure.

With the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for carrying out the invention as defined by the following claims. All art-known functional equivalents, of any such materials and methods are intended to be included in this invention. Notwithstanding this, we appreciate that other variations and modifications may be perceived and made by those skilled in the art, and it is our intention that all such other variations and modifications will be understood to be within the spirit of the invention and the following claims.

Claims

A novel strength-decoupled high elastic modulus cementitious composite characterized in:

exhibiting superior high elastic modulus mechanical properties value of 40GPa～50GPa with modest strength mechanical properties value of 40MPa～80MPa;

promoting uniformity of deformation by avoiding strain localization and strength-decoupling behaviour by the microstructure of harmonic-structured cementitious matrix phase dominating over the strength development from aggregate skeleton inclusion phase;

being made up of an unique harmonic-structured cementitious matrix phase formed by the solidification of heterogeneous binary hydraulic cementitious binder with specific spatial topologically arranged bimodal core-shell cluster of Coarse Grain Core particles material and Ultrafine Grain Shell particles material;

an organized network structure of continuously connected compact form cementitious hydrate gel morphological transformed from confinement based topochemical hydration reaction process of Ultrafine Grain Shell particles material encapsulating Coarse Grain Core particles material with addition of water and organic structure-directing functionalizing agents; being further comprise latent hydraulic-pozzolanic cementitious matrix filler phase, coarse-to-fine powder-aggregate skeleton inclusion phase, soft organic dispersing agents and optionally organic-metallic fibre reinforcement phase based on the composite rule of mixture proportioned under low water/cementitious binder-filler ratio;

the distribution of bimodal core-shell cluster of Coarse Grain Core and Ultrafine Grain Shell particles material being engaged with the weight ratio of 75%-45%of coarse grain with scale range mean diameter equal and or greater than ‘10’ microns; preferably in-between ‘10’ to ’40’ microns; even more preferably in-between ‘20’ to ’30’ microns, and with the weight ratio of 25%-55%of ultrafine grain scale with scale range of mean diameter equal and or smaller than ‘10’ micron; more preferably in-between ‘3’ to ’10’ microns; even more preferably ‘5’ to ’7’ microns;

the Coarse Grain Core particles material containing hydraulic reactive calcium silicates and calcium aluminate silicates building units being manufactured from typical Portland cement clinker grinding process;

the Ultrafine Grain Shell particles material containing hydraulic reactive calcium aluminate silicates building units being manufactured from mechano-chemically activated grinding process of granulated blast furnace slag with high aluminium oxide (AL2O3) content equal or greater than 10%and optional with natural and or manmade zeolite powders;

the mechano-chemically activated shear and friction grinding process of granulated blast furnace slag comprising the steps of using dry agitator bead mill assisted with organic dispersant agent containing alkanol amine;

during the composite mixing process, the Ultrafine Grain Shell particles material surfaces being functionalized by cationic organic structure directing agent containing quaternary ammonium surfactants forming shell layer of the core-shell skeleton network topology with the Coarse Grain Core particles materials;

the water/hydraulic cementitious binder-filler ratio being set in the range of 0.28～0.35 to confine the space volume for hydration growth and subsequent hydrate solidifying morphology;

by adding controlled water with soft organic dispersing agents, the main species in the harmonic-structured cementitious phase, ultra-high and high elastic modulus C-S-H and or C-A-S-H hydrates, being spontaneous precipitately produced with the space confinement interaction between the Ultrafine Grain Shell particles layers and Coarse Grain Core particles rims;

by latent hydraulic-pozzolanic filler matrix phase and coarse-to-fine aggregate skeleton inclusion phase being subdivided into fine and coarse fractions for controlling micro-architecture of strength-decoupled high elastic modulus cementitious composite.
The strength-decoupled high elastic modulus cementitious composite of Claim 1, further characterized in having the heterogeneous binary hydraulic binder with:

the particle size distribution of Coarse Grain Core particles material and Ultrafine Grain Shell particles material having numbers of peak, i.e., plurimodal, but at least has two peaks and preferably is essentially a bimodal distribution, i.e. at least 80% (preferably 90%) by volume of the particles are associated with the two peaks;

the relative volume of the particles in the first peak relative to the volume of the particles in the second peak is from 2.5: 1.0 to 1.0: 1.0, more preferably 1.5 to 1.0;

preferably the Coarse Grain Core particles material and the Ultrafine Grain Shell particles material have substantially similar hydraulically reactivity for creating dense bimodal core-shell clusters with order and directing the topochemical hydration process while solidification and generation of an organized network structure.
The strength-decoupled high elastic modulus cementitious composite of Claim 2, further characterized in:

the Ultrafine Grain Shell particles material being produced by dry agitator bead milling of Ground granulated blast furnace slag (GGBS) in associated with polymer co-dispersant containing at least one type of “alkanol amine” preferably diethanol isopropanolamine (DEIPA) as grinding activation agent;

the high aluminium oxide (AL2O3) content of the ground granulated blast furnace slag (GGBS) ranging from 10%to 20%, preferably 13%to 17%; more preferably 13%to 15%;

the Ultrafine Grain Shell particles material particle size distribution has one single peak of “5’ micron in size at least greater than 50%; more preferably greater than 60%; even more preferably greater than 70%by volume of the particles associated with this single peak.
The strength-decoupled high elastic modulus cementitious composite of Claim 1, further characterized in:

the organic structure-directing agent executing its structure-directing function on the the Ultrafine Grain Shell particles material lead to core-shell maximum packing structures developing;

the organic structure-directing agent having high positively charged electrostatic force effectively attracting negatively charged Ultrafine Grain Shell particles and structure-directing the Ultrafine Grain Shell particles to a more homogeneous than a random mixture with Coarse Grain Core particles in high rheological behaviour;

the organic structure-directing agent being a cationic polymer surfactant containing quaternary ammonium compounds such as triquaternary amine for directing the shell layer formation of the core-shell skeleton network topology derived from the Coarse Grain Core particles material and Ultrafine Grain Shell particles material;

the quaternary ammonium type organic structure-directing agent thereby formed by compounding a polymer A and a compound B, wherein the polymer A is obtained by free radical copolymerization of a monomer “a” and a monomer “b” , the monomer ”a” is selected from mixtures of (meth) acrylic acid or monovalent metal salts of (meth) acrylic acid in any ration, and monomer “b” is selected from diallyl quaternary ammonium slat derivatives or (meth) acrylic acid amide quaternary ammonium salt derivatives; and the compound B is fatty acid alkanolamide.
The strength-decoupled high elastic modulus cementitious composite of Claim 3, further characterized in:

the mechano-chemical activation of granulated blast furnace slag being executed by shear and friction based grinding process;

the shear and friction based grinding is a dry grinding process to be executed in a horizontal type agitator bead mill;

the dry mode horizontal type agitator bead mill is equipped with special agitator elements transversely arranged with predetermined spacing on a horizontal rotating shaft driven by medium to high speed rotor;

the special agitator element is a die cast type metal disc with proprietary shape configuration wherein the outer edge of each agitator element extends as a planar spiral expanding in a direction opposite to that of its intended rotation so that the grinding bodies roll on a contact line with low gradient;

the Ultrafine Grain Shell particles material dry grinding process being executed by means of shear and friction mode in lieu of compression mode through random relative comminuting media balls motion action induced by planar spiral shaped agitator elements/discs uniformly arranged along rotating agitator shaft;

the mechano-chemical activation of granulated blast furnace slag being assisted by organic surface-active surfactant containing at least one type of alkanol amine preferably being DEIPA ‘N, N-bis (2-hydroxyethyl) -2-propanolamine.
The strength-decoupled high elastic modulus cementitious composite of Claim 2, further characterized in:

the Coarse Grain Core particles material being selected from the group of Portland cement, Portland composite cement, and blast furnace slag cement.

the Ultrafine Grain Shell particles material being selected from the group of blast furnace slag cement optioned with zeolite powder addition as catalyst agent;
The strength-decoupled high elastic modulus cementitious composite of Claim 1, further characterized in:

the latent hydraulic filler matrix phase being pozzolanic supplementary cementitious materials selected from the group of silica fume, flyash to consume excess portlandite CA (OH) 2 after the hydration;

the coarse-to-fine aggregate skeleton inclusion phase being non-reactive stone filler materials selected from the group of granite, limestone and calcined bauxite;

the organic polymeric dispersing agents are tailor-made anionic comb copolymers selected from the group of polycarboxylates and polyphosphonate anchor groups with polyether side chains as flow enhancers for low water-to-cementitious binder-filler ratio.
The strength-decoupled high elastic modulus cementitious composite of Claim 1, characterized in that the method for manufacturing is comprising the steps of:

(i) dry grinding of Portland cement clinker and/or granulated blast furnace slag materials into Coarse Grain Core particles material with particle size distribution (d95) ranging from 20 to 70 μm micron and with specific surface areas ranging from 0.3 to 0.8 m2/g;

(ii) dry agitator mill grinding with polymer co-dispersant “alkanolamine” of granulated blast furnace slag coarse grain materials into ultrafine grain hydraulic binder material with particle diameter (d95) in the range from 2 to 20 μm micron and specific surface areas in the range from 0.9 to 5 m2/g;

(iii) providing a mixture of heterogeneous binary hydraulic binder with unique bimodal distribution from the Coarse Grain Core particles material and the Ultrafine Grain Shell particles material;

(iv) base on the rule of mixing, adding latent hydraulic-pozzolanic filler matrix phase, coarse-to-fine aggregate inclusion phase and optionally organic and/or metallic fibre reinforcing phase into the heterogeneous binary hydraulic cementitious binder;

(v) adding organic structure directing agent containing quaternary ammonium surfactant into the mixture for forming self-assembly bimodal core-shell clusters with controlled and specific topological particles distribution of Coarse Grain Core particles material and Ultrafine Gain Shell particles material;

(vi) adding water, flowing enhancing agents containing anion support polyether chains and/or other additives based on the optimized global packing density water/cementitious binder-filler ratio requirement for confinement solidification;

(vii) processing the above pre-determined mixture mixing with blending mixer, and

(viii) the strength-decoupled high elastic modulus cementitious composite is manufactured.
The strength-decoupled high elastic cementitious composite of Claim 1, characterized in making the use of structural components and/or elements in forming in-situ and/or prefabricated reinforced cementitious composite components with:

the low Portland cement content in the range of 200kg-300kg, and more preferably 250kg-275kg per cubic meter cementitious composite;

a combination of modest compressive strength in the range of 45MPa-80MPa, and high elastic modulus in the range of 40GPa-50GPa;

using optimized water/cementitiou binder-filler ratio in the range of 0.28-0.35, and more preferably in the range of 0.30-0.33 for high durability and early age strength performance;

using optimized packing density and high performance superplasticizer dispersant agents with a combination of carboxylate and phosphonate anion anchor groups for high workability performance.
The strength-decoupled high elastic cementitious composite of Claim 1, further characterized in substantially as hereinbefore described with reference to the accompanying drawings.