CN113372084A

CN113372084A - Preparation method of eggshell sand imitation lattice building block

Info

Publication number: CN113372084A
Application number: CN202110828827.1A
Authority: CN
Inventors: 孙宁波; 吕海波; 刘海顺
Original assignee: Urumqi Shengda Tianli Building Material Technology Co ltd
Current assignee: Urumqi Shengda Tianli Building Material Technology Co ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2021-09-10

Abstract

A light high-strength building block is prepared through coating egg shell sand with trace welding agent, spreading it in mould according to lattice structure, and ultrasonic vibration to weld the cut surface. The microstructure of the imitated crystal lattice obtains the mechanical property of the crystal lattice and realizes the purposes of light weight and high strength of the building block. The actual measured bulk density of the building block is less than or equal to 350kg/m³The compressive strength is more than or equal to 4.5 MPa.

Description

Preparation method of eggshell sand imitation lattice building block

Technical Field

A preparation method of eggshell sand imitated lattice building blocks belongs to the field of silicate materials and buildings.

Background

From soil blocks to bricks, to haydite blocks and aerated blocks. In the industry, the interior of the building block is always tamped, vibrated and foamed, so that the internal structure is never concerned, and the block is continuously manufactured in a rough way. Perhaps the material is too inexpensive to justify this. The steel is difficult to be obtained and smelted. Therefore, various steel structures have come into play through careful study and careful carving. Is not light and only saves money. However, the building blocks are needed to be stronger and lighter, and the internal microstructure of the building blocks is not necessarily researched. Not to save money but to be lighter. The volume weight is less than or equal to 350kg/m³The inorganic homogeneous building block with the compressive strength of more than or equal to 4.5MPa is difficult to realize in the prior art.

Disclosure of Invention

The scale production of the autoclaved eggshell sand lays a foundation for the light and high-strength building blocks

The forming method of forming the crystal-like lattice microstructure by using the eggshell sand is researched, and a simple die is selected for forming. The laying method of the eggshell sand in the mold is researched, and two laying methods which are laid into an imitation lattice compact structure or an imitation lattice non-compact structure by taking a layer as a unit are formed. Two building block products with different structures and different mechanical characteristics are formed. The method for bonding the sections of the eggshell sand is researched, an adhesive consisting of cement, mineral powder, quartz sand and redispersible rubber powder is compounded, and the mixing proportion of the eggshell sand, the adhesive, water and a water reducing agent is screened out. A pre-forming process for coating the adhesive on the surface layer of the eggshell sand by a roller type stirrer in a stirring method is selected. Further, a technology of allowing the adhesive coated on the surface layer of the eggshell sand to flow and adhere to the section gaps among the eggshell sand by vibration, exhausting air and forming compact welding spots is studied. The process of demoulding the block blank to form a blank was investigated. The demolding method is that 4 side vertical surfaces are detachable and the base is reserved. Preferred are release agents formulated with soap and motor oil. In order to improve the production efficiency, the scheme that the base with the building block blanks are put into the steam curing kiln together is adopted, and the steam curing scheme is selected to improve the single-day capacity.

The previous research is seemingly smooth, but the building blocks show compressive strength, the upper part and the lower part are different, the deviation is too large, and the eggshell sand building blocks are further found to have different structural volumes, upper density and lower density and layered. Various methods, such as rolling dies, have been tried, but all have failed. The fact that the intensity deviation is unacceptable in the application scene means that the industrialization of the project is hindered. Later attempts to use ultrasonic vibrator wands had improved the intensity bias. It can be understood that the adhesive slurry coated on the eggshell sand is thrown out or off the surface layer of the eggshell sand due to the large-amplitude vibration slurry, and under the action of gravity, the welding agent is accumulated towards the bottom of the building block, the larger the amplitude is, the longer the vibration processing time is, and the more prominent the deposition performance at the bottom of the welding agent is. The ultrasonic vibration frequency of ten kilohertz is far higher than that of a high-frequency vibration plate of hundreds of hertz, the amplitude of the ultrasonic vibration is reduced to micron level, the vibration of the amplitude can not throw off the adhesive coated on the eggshell sand, and therefore the downward deposition of the welding agent is not obvious. The welding agent coated on the eggshell sand flows along the wall under the external force of ultrasonic vibration, and stays and exhausts in the section between the eggshell sand, thereby forming a compact section welding point. The micron-sized amplitude is very suitable for welding agent seam drilling, the ultrasonic frequency oscillation also shortens the processing time from tens of seconds to several seconds, and the formula adjustment of the welding agent is matched, so that the dense welding of a tangent plane is further realized, the using amount of the welding agent is reduced, the building block is lighter, and the strength is better. The mould has further been improved, installs the piezoceramics piece on the mould side panel, has realized the direct coupling of ultrasonic oscillation source and material. Different ultrasonic waveforms, frequencies, were tried. The matched high-power ultrasonic square generator is customized, the defects are thoroughly overcome, and the industrial bottleneck is broken through.

The preparation method of the eggshell sand crystal-imitated building block is further optimized, the eggshell sand which is saturated and absorbs water is drained, the drained eggshell sand is placed into a stirrer, 0.3/D-0.9/D kilogram of welding agent is added into each liter of eggshell sand and stirred for 5-15 min, the eggshell sand which is stirred with the welding agent is layered and is orderly paved in a mold according to a compact shape or a non-compact shape, an ultrasonic generator is opened for 3-9 sec, four side vertical surfaces of the mold are disassembled, a building block blank body and a mold base are placed into a steam curing chamber together, steam is introduced into the steam curing chamber, constant-temperature curing is carried out for more than 8h, the steam cured building block blank body is taken out, and the eggshell sand crystal-imitated building block is obtained after drying to a constant weight. The block preparation is achieved in 7 process steps. The eggshell sand saturated water absorption method is optimally adopted, the saturated water absorption is defined to absorb water to constant weight or be soaked for more than 1 hour, the draining of the eggshell sand saturated with water is further determined, and no water drops in the eggshell sand draining net within 60 sec. The quality of the welding agent added into each liter of eggshell sand is simplified, a simple calculation formula is calculated, 0.3/D-0.9/D kilogram of welding agent is added into each liter of eggshell sand, D is the diameter of the eggshell sand, and the unit is mm. The welding agent is optimized to be composed of 35-45 parts of portland cement clinker, 0.3-0.5 part of gypsum, 25-35 parts of mineral powder, 45-65 parts of 200-mesh quartz sand, 0.25-0.5 part of redispersible rubber powder, 3-15 parts of polycarboxylic acid water reducing agent and 33-42 parts of deionized water, and the die is definite in that a piezoelectric ceramic piece is installed on one side vertical face, and iron, aluminum or plastic dies which can be disassembled on four side vertical faces are detachable. The ultrasonic generator is a high-power ultrasonic generator with a power output end connected to a piezoelectric ceramic piece of the die, and the output waveform is a square wave with the frequency of 110000 Hz-220000 Hz; the steam curing is definitely not more than 70 ℃ steam curing; the drying before the product detection is determined to be drying at 60-85 ℃ to constant weight.

Drawings

FIG. 1 is a schematic diagram of an arrangement of lattice-like densely packed eggshell sands; FIG. 2 is a schematic diagram of an arrangement of lattice-simulated non-densely packed eggshell sands

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Taking a laboratory sample block as an example, and combining the attached drawings, the preparation method of the light high-strength building block with the eggshell sand imitation lattice structure is explained in detail;

experimental equipment: 100X 100 detachable aluminum alloy triple die, small ball mill, 100 mesh vibrating screen, roller stirrer, customized 50W, 175000Hz ultrasonic square generator, phi 5050W piezoelectric ceramic sheet, 15L soaking barrel and steam curing chamber

Preparing eggshell sand raw materials: 10L of 5-0.2 eggshell sand with the shell thickness of 0.2mm and the outer diameter of 5mm and 10L of 10-0.3 eggshell sand with the shell thickness of 0.3mm

Preparing a welding agent powder material: 100g of portland cement clinker, 2g of gypsum, 40g of mineral powder, 120g of quartz sand and 10g of redispersible rubber powder, putting the raw materials into a ball mill, carrying out ball milling for 1h, discharging and sieving by a 100-mesh sieve for later use

Preparing a liquid solder material: 132g of deionized water and 14g of polycarboxylic acid water reducing agent are mixed and stirred uniformly for later use

Preparing a mould: washing a groove with the depth of phi 50 mm in each center of the side baffle, drilling a phi 3 through hole in the center, mounting a piezoelectric ceramic piece, leading out a lead from the central through hole, sticking the piezoelectric ceramic piece in the groove by using polyurethane glue, keeping the same with the plane in a mold, mounting the mold, coating a release agent mixed by soap and engine oil, and connecting the piezoelectric ceramic piece to the output end of an ultrasonic generator

Putting the eggshell sand into a barrel, soaking for 1h, and draining for later use

The welding agent powder and the liquid are mixed and stirred evenly for standby

Preparation for making blank of building block

Example 1 compact form 5-0.2

Taking 3L of drained 5-0.2 eggshell sand, adding 150g of welding agent, stirring for 6min, stopping the machine, paving the eggshell sand in a close-packed manner in a mould according to a layer as shown in figure 1, simultaneously opening an ultrasonic generator, vibrating for 5sec, standing for 10min, opening the mould, and removing two side baffles and two plugs

Example 2 non-compact form 5-0.2

Taking 3L of drained 5-0.2 eggshell sand, adding 150g of welding agent, stirring for 6min, stopping the machine, laying in a non-compact form in a mould according to a layer, simultaneously turning on an ultrasonic generator, vibrating for 5sec, standing for 10min, opening the mould, removing two side baffles and two plugs

Example 3 compact form 10-0.3

Taking 3L of drained 10-0.3 eggshell sand into a roller stirrer, adding 75g of welding agent, stirring for 6min, stopping the machine, paving the eggshell sand in a compact layer in a mould shown in figure 1, simultaneously opening an ultrasonic generator, vibrating for 5sec, standing for 10min, opening the mould, and removing two side baffles and two plugs

Example 4 non-compact form 10-0.3

Taking 3L of drained 10-0.3 eggshell sand, adding 75g of welding agent, stirring for 6min, stopping the machine, paving in a non-compact form in a layer in a mould as shown in figure 2, simultaneously turning on an ultrasonic generator, vibrating for 5sec, standing for 10min, opening the mould, removing two side baffles and two plugs

And (3) simultaneously putting the 4 groups of blanks into a steam curing chamber, adjusting the temperature control setting to 70 ℃, starting steam curing for 7 hours, taking out the blocks, and drying at 85 ℃ to constant weight.

The result of the detection

Example 1: average volume weight of 312kg/m³Compressive strength max5.23MP, normal compressive strength of 51.25kN, compressive side of 51.22kN and compressive strength of 45 kN^ODiagonal line 37.76kN

Example 2: average volume weight of 304kg/m³Compressive strength max5.62MP, compressive normal 55.08kN, compressive side 55.02kN, compressive 45 kN^ODiagonal line of 17.86kN

Example 3: average volume weight 217kg/m³Compressive strength max4.52MP, compressive normal pressure of 44.3kN, compressive side of 54.55kN and compressive side of 45 kN^ODiagonal line 39.32kN

Example 4: average volume weight 203kg/m³Compressive strength max4.65mp, compressive normal 45.57kN, compressive side 54.13kN, compressive 45^ODiagonal 11.54 kN.

Claims

1. A method for preparing the lattice-imitated building block of eggshell sand features that the building block is prepared from eggshell sand through spreading in lattice structure, and ultrasonic vibration welding with less welding flux.

2. The method for preparing the eggshell sand imitation lattice building block according to claim 1 comprises the steps of draining saturated and water-absorbing eggshell sand, putting the drained eggshell sand into a stirrer, adding 0.3/D to 0.9/D kilogram of welding agent per liter of eggshell sand, stirring for 5 to 15min, layering the eggshell sand stirred with the welding agent, neatly paving the eggshell sand in a mold according to a compact or non-compact shape, opening an ultrasonic generator, carrying out high-frequency ultrasonic vibration for 3 to 9sec, dismantling four side vertical surfaces of the mold, putting a building block blank and a mold base into a steam curing chamber, introducing steam into the steam curing chamber, carrying out constant-temperature curing for more than 8h, taking out the steam cured building block blank, and drying to constant weight to obtain the eggshell sand imitation lattice building block.

3. The saturated water absorption according to claim 2 is that the eggshell sand absorbs water to constant weight or is soaked for more than 1 h; the draining is that no water drops within 60sec of the eggshell sand draining net; d is the diameter unit of the eggshell sand is mm; the welding agent comprises 35-45 parts of portland cement clinker, 0.3-0.5 part of gypsum, 25-35 parts of mineral powder, 45-65 parts of 200-mesh quartz sand, 0.25-0.5 part of redispersible rubber powder, 3-15 parts of polycarboxylic acid water reducer and 33-42 parts of deionized water; the die is an iron, aluminum or plastic die with one side vertical surface provided with a piezoelectric ceramic piece and four detachable side vertical surfaces; the ultrasonic generator is a high-power ultrasonic square generator with the output end connected with the piezoelectric ceramic, and the output frequency is 110000 Hz-220000 Hz; the steam curing is steam curing at the temperature of less than or equal to 70 ℃; the drying is carried out at the temperature of 60-85 ℃ to constant weight.