WO2000001899A1

WO2000001899A1 - Protection procedure against capillary moisture in constructions without settlement or cracks using a load-bearing watertight plastic barrier placed in massive walls

Info

Publication number: WO2000001899A1
Application number: PCT/YU1998/000020
Authority: WO
Inventors: Stevan Oberknezev
Original assignee: Stevan Oberknezev
Priority date: 1998-07-01
Filing date: 1998-11-02
Publication date: 2000-01-13
Also published as: DK1042565T3; PT1042565E; YU49324B; YU27398A; ES2259215T3; ATE318349T1; DE69833563T2; EP1042565A1; DE69833563D1; AU1421899A; EP1042565B1

Abstract

Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2 and their application technique are designed for rehabilitation and preservation of old civil engineering structures and monuments after step-by-step horizontal cutting of wet walls damaged by capillary moisture. The barrier joints are connected in the cut via their male (MC) and female (FC) end couplings and, interlocked, driven into the cuts filled with viscous cement mortar. Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2 of infinite length fulfill three functional targets: the horizontal plate (a) acts as a watertight barrier or damp-proof course that prevents moisture movement by capillary forces into the parts above the cut, the male (MC) and female (FC) couplings tightly interlock the individual barrier joints and, once the barrier joints are interconnected and fitted into the wall cuts, they provide an unbreakable and impervious tie that is integral to the barrier system, while the vertical fins (F), perpendicular to the plate (a) support the total vertical load of the upper section of the treated civil engineering structures removing all hazard from fracturing or microfissuring.

Description

PROTECTION PROCEDURE AGAINST CAPILLARY MOISTURE IN CONSTRUCTIONS WITHOUT SETTLEMENT OR CRACKS USING A LOAD-BEARING WATERTIGHT PLASTIC BARRIER PLACED IN MASSIVE WALLS

designed to provide damp walls with watertight protection, old buildings and monuments with new damp— proof course that controls capillary moisturizing

(Product, barrier installation method and technique)

SCOPE OF TECHNICAL APPLICATION

Civil engineering,

Rehabilitation of buildings affected by moisture attack,

Rehabilitation and preservation of buildings and monuments of historical and cultural value,

Protection of buildings from capillary moisture and groundwater,

Postconstructional fitting of new waterproof barrier,

Postconstructional establishment of new damp-proof course for control of wall moisturizing by capillary and osmotic forces,

Machine cutting of damp walls and insertion of a new damp-proof course; fitting of Plastic Profiled Semi— Rigid Barrier to prevent capillary moisturizing.

The technical solution provided by this invention consists of targeted, mechanical and stepwise cutting through damp walls of civil engineering structures and monuments attacked by capillary moisture and of furnishing the horizontal cuts with the proposed PVC barrier that acts as a new damp-proof course or waterproofing system, preventing wetting by capillary forces and subsidence that is commonly followed by fracturing of the treated walls.

According to MKP (5), the invention may be classified E 04 B 1/62; E 04 F 21/00; E 04 G 9/10; E 04 G 23/06.

TECHNICAL PROBLEM

The technical solution provided by the subject invention and technique is in that the damp walls are mechanically, in a stepwise procedure, bisected at the target level (wall thickness and building material are irrelevant issues in the application of this patent) and the damp-proof barrier is fitted as a new waterproofing system that prevents rising of capillary water and wall wetting. When the damaged wall is cut and the barrier installed, the system - owing to its inherent properties - assumes the load of the superposed section, prevents subsidence and possible fracturing or fissuring of the treated structures.

STATE OF ART

Patent and other documentation show that several methods are applied in the efforts to rehabilitate and preserve civil engineering structures damaged by capillary moisture, particularly structures of historical value. — Giovanni Massari Method

The technique is based on penetrating the wall by overlapping sequences of horizontal holes bored with cylindrical, diamond-bit tools and injection of a flour and fine-grained sand blend bonded with polyester resin. Note that the polymerization of the fill is completed in three to four hours.

The disadvantages of this method include time-consuming and expensive boring of many holes, incomplete control of bore filling, limitations imposed by wall thickness (untreatability of walls thicker than 130 cm), and frequent fracturing and fissuring of the injected waterproofing system due to differential structure settlement.

Also, the method is inapplicable to old structures built of different materials (brick+stone+brick) or to loose or insufficiently compacted walls.

- HW Method

The rehabilitation is based on direct insertion (driving in) of corrugated prochrome steel sheets as moisture barriers with a vibrating power press through wall joints.

The major disadvantage of this method is that the structure is subjected to serious vibrations that may damage its stability and load capacity. Also, the overlaps are often unreliable and provide incomplete protection in cases when any minor lack of unbroken unity allows moisture penetration. Added to the high cost of prochrome sheets, subsidence and resulting wall fracturing are other disadvantages of this method.

- COMER Method

The wall is cut only at the joints; cutting widths range from 20 to 120 cm and cut heights from 8 to 14 mm. The cuts are fitted with waterproof material, either bituminous bands, technical PVC foils or plasto-elastic fiberglass sheets (made of glass voile and epoxy resin). The bands are cut and placed to overlap for 5 to 10 cm. To prevent wall subsidence, plastic inserts, "zeppas", are fitted perpendicular to the wall axis as temporary load supports until the injected mortar-plus-additive (expander) blend sets.

The disadvantage of this procedure is that it does not allow rehabilitation of very massive walls, the thickness of which exceeds 130 cm. Nor can it be applied to stone walls or walls built in brick-and-stone mix. Differential structure subsidence and fracturing of treated walls have been frequently observed as a result of fairly poor support of the walls by the inserted zeppas.

- UMIBLOK Method

The method requires horizontal, 12 to 16 mm high cuts in 20 to 50 cm wide intervals with self-propelled machines. After cleaning the cuts, viscous cement mortar, with accelerators and expanders added to the slurry, is injected. This is followed by successive assembling and fitting of UMIBLOK bars, an operation that has to be completed before the slurry sets.

The 8 mm high, PVC, UMIBLOK bars with rigid beveled profiles are extrusion products. The essential scope of their application is waterproofing.

The disadvantage of the method, other than that inherent to the UMIBLOK bar itself, specifically to its shape and structure, is that its sole purpose is waterproofing, the establishment of a damp-proof course. The load of the structure above the cut is to be supported by the injected mortar. Another disadvantage is the hazard of microfissuring. Last, but not least, the installation procedure is difficult and complicated because of new mortar properties. Additives are used to accelerate bonding and the insertion of the bars has become a difficult task.

All of the listed problems and disadvantages are successfully overridden by applying the new method and product described in these patent documents.

PATENT DESCRIPTION

The gist of the invention and method is the Plastic Profiled Semi-Rigid Barrier. Barrier joints are interlocked into a single and continuous horizontal plate that bars all moisturizing by capillary and osmotic forces. The shape, structure and other relevant features of the barrier allow fitting into wet walls. The product - Plastic Profiled Semi-Rigid Barrier - is patented conjointly with the method and procedure of rehabilitating buildings and monuments damaged by the harmful effects of capillary moisture.

The Plastic Profiled Semi-Rigid Barrier solves two (2) crucial problems: a) once fitted into the wall cut, it acts as an impervious, waterproof barrier, and b) prevents structure subsidence.

Structure rehabilitation and barrier installation are achieved applying the following procedure.

The walls wet with capillary moisture are bisected using one of the alternative cutting techniques:

1. classical brick and lime-mortar walls are cut with such electrical or power tools that are equipped with bar and Widia chain and that are operated at wall joints. Alternatively,

2. stone and mixed material (brick + stone) walls are cut with power tools and diamond wire saw at the target height regardless of the position of wall joints.

Cut height, CH, is a variable dependent on the cutting tool; cut heights may be 8.00; 9.00; 11.00; 12.00 or 16.00 mm (Fig. 3).

A high-pressure pump forces the viscous slurry of cement mortar with plasticizer and retarder added into the created cuts. The performance of these additives are opposite to those in the UMIBLOK® method that employs accelerators and expanders. The here described method requires superplasticizers and retarders to provide the viscous cement mortar with superplasticity and to prolong the wait-on-cement time for 8 to 10 hours. Special and long enough 'needles' allow positive filling along and across the wall cut. The Plastic Profiled Semi— Rigid Barrier joints are lightly hammered into the cuts filled with the cement slurry. The barrier joints are securely connected by male (MC) and female {FC) couplings. The injected mortar slurry completely coats and embeds the barrier so that, after cement setting and crystallization, the components of the system create a strong, compact, monolith and watertight protection. Temporarily or until the injected slurry fully sets, the vertical fins (F) support the load of the structure above the cut. Thus, the combined load capacity of the barrier and the injected mortar completely substitutes the wall joint.

EXAMPLE

A. / >t7~ . fym-ffl-uwt π-ϊ . i ytmryt -H eitr12UtftH (f ig. 3 oi J* lg. 4

Let the wet wall be of brick and lime mortar and let the wall thickness, t, be 130 cm. The wall is cut at the joint with Widia chain. In this case, the typical cut height is 12 mm.

The wall is cut in stages, cutting interval width being approximately 50 to 60 cm depending on the state of the wall. The total cut height is mechanically cleaned to remove mortar or brick particles, or their aggregates. A pressure pump forces additive enriched, cement-mortar slurry into the clean cut, the additives being superplasticizers and retarders.

The retarder allows ample wait-on-cement time and removes the risk of premature and uncontrolled cement mortar setting. The retarder postpones setting for some eight to ten hours making frequent pump cleaning unnecessary. The pumps are cleaned and washed once a day, by the end of the working hours.

B. fynwa iamarm πiψ f/wtπ C/ ,IMOΛ-H Λ^ Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2

Let the total Plastic Profiled Semi-Rigid Barriers No. 1 and No 2 width be w, their length X and fin, JF, height h.

In the example, cut height, CH, is set at 12 mm and wall thickness, t, at 130 cm. The barrier- joint length, X, is cut to D I = 140 cm (DL1 =DL + 5 + 5 cm). The short joint is precision ground to hi =12.20 mm.

When the height of the barrier joint is adjusted to hl =12.20 mm, the first joint is fitted into the cut {CH=12.00 mm) infilled with the injected slurry, by lightly tapping with a hammer. The excess fin height, Ahl (Ahl =0.20 mm) completely prevents structure subsidence. The whole operation, from cutting through cleaning and joint preparation to installation, is easy and provides quick rehabilitation of extremely massive walls.

The following figures present the invention in full details:

* Fig. 1 - Axonometric presentation of prefabricated Plastic Profiled Semi-Rigid Barrier No. 1.

* Fig. 2 - Axonometric presentation of prefabricated Plastic Profiled Semi-Rigid Barrier No. 2.

* Fig. 3 - Wall after fitting of Plastic Profiled Semi-Rigid Barrier No. 2.

* Fig. 4 - Wall after fitting of Plastic Profiled Semi-Rigid Barrier No. 2. * Fig. 5 - Plastic Profiled Semi-Rigid Barrier No. 1 cross-section.

* Fig. 6 - Plastic Profiled Semi-Rigid Barrier No. 1 cross-section, coupling and coupling detail.

* Fig-. 7 - Plastic Profiled Semi-Rigid Barrier No. 2 cross-section.

* Fig. 8 - Plastic Profiled Semi-Rigid Barrier No. 2 cross-section, coupling and coupling detail.

Fig. 1 shows the Plastic Profiled Semi— Rigid Barrier No. 1. The Plastic Profiled Send—

Rigid Barrier No. 1 is an extruder product made essentially in rigid polyvinylchloride (PVC) enriched with various additives to improve its mechanical properties like hardness, strength, toughness, elasticity, impermeability, and to enhance its resistance to the harmful action of aggressive chemicals like acids, alkalis and salts. Some additives serve to neutralize thermal effects; the UV stabilizator improves the resistance to ultraviolet radiation.

Fig. 2 shows the Plastic Profiled Semi-Rigid Barrier No. 2 identical with respect to material composition, chemical and physical properties and mechanical performance to Barrier No. 1. The shape and design of the female coupling (FC) make the only difference. In the case of Barrier No. 2 the FC is a semi-open sphere, SS, stronger and more rugged. As the barriers are extruded, the length, X, of a barrier joint is not limited.

The profile, shape, size, number, height, thickness and spacing of the fins, F, are designed so that the fins can assume the total load of the structure above the cut during barrier fitting. Also, their profile allows unobstructed penetration into the injected mortar throughout the fitting operation.

The Plastic Profiled Semi— Rigid Barriers No. 1 and No. 2 (Figs 1, 2, 3, 4, 5, 6, 7 and 8) are both designed and made so that their length X may be theoretically infinite. The barriers consist of a plane plate denominated α; their total width is W, their wall thickness t. For the barrier to support the vertical load of the cut wall, the horizontal plane of the plate a is intersected with a sufficient number of vertical fins, F, at S intervals or spacing. Wall thickness, t, is identical to the thickness of plate a. Total fin height is h. Fin spacing, S, and wall thickness, t, are variables in function of the calculated load and static load capacity of the Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2. The barrier joints are interconnected via male and female couplings (MC and FC, respectively) to form a permanent and unbreakable tie.

The male coupling, MC, is a cylinder, C; its diameter is denoted d. Cylinder C is an integral part of the horizontal plate, a, and its length equals the length of the barrier, X.

On the other hand, the design of the female coupling, FC, depends on the barrier type.

1. In the case of the Plastic Profiled Semi-Rigid Barrier No. 1 (Fig. 5 and 6) the coupling is a semi-open, rectangular, pentagonal box of infinite length X. One end of the female coupling, FC, is made integral part of the barrier or, more specifically, of its horizontal plate, α. The other end has two inward bent, semi-open claws, K. The clearance, c, between the tips of the claw, K, corresponds to the diameter, d, of the cylinder, C, increased for 0.50 mm (c = d + 0.50 mm). The distance between the tips, cl , of the semi-open claw, K, corresponds to the barrier wall thickness, t, increased for 0.50 mm (cl = t + 0.50 mm). These tolerances completely satisfy and justify both of the set targets: ease of coupling and unbreakable connection. 2. In the case of the Plastic Profiled Semi-Rigid Barrier No. 2, (Fig. 7 and 8) the coupling cross-section is a spherical semi-open box of infinite length X. One end of the coupling is an integral part of the barrier plate as it is continuous with the plane of the horizontal plate a. The other end, designated SPH, is semi-open, spherical and bevel tipped. The diameter d of the SPH sphere corresponds to the diameter, d, of the cylinder, C, increased for 0.50 mm (dl =d+0.50 mm). The clearance, c2, of the SPH semi-open sphere corresponds to the barrier wall thickness, t, increased for 0.50 mm (c2=t+0.50 mm). These tolerances completely satisfy and justify the two target functions: ease of connecting the MC and FC set and positive, unbreakable connection.

Claims

PATENT CLAIMS

1. Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2 are horizontal waterproofing barriers or damp-courses designed for rehabilitation and preservation of civil engineering structures attacked by capillary moisture. The product DEFINED AS ABOVE is made by extrusion of rigid polyvinylchloride (PVC) enriched with additives that improve its physical and chemical properties. The barrier consists of a horizontal plate, ╬▒, intersected by an adequate number of vertical fins, F, of total height, h, at set spacings, S. The thicknesses of the horizontal plate, a, vertical fins, F, and of the male and female couplings, MC and FC, respectively, are identical and denoted t. The length of the Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2, X, is infinite, their widths denoted W. The W ends of the horizontal plate a continue into male (MC) and female (FC) couplings. The male coupling is a cylinder, C; its diameter is d, its infinite length X. The cylinder, C, and the female coupling, FC, are integral parts of the horizontal plate, ╬▒. The female coupling, FC, of barrier No. 1 is designed to form an inward bent claw, K, with claw clearance e (c=d+0.50 mm) and claw tip clearance cl (cl =t=0.50 mm). The FC of barrier No 2 is a bevel ended semi-open sphere, SPH. The diameter, dl , of the spherical female coupling, SPH is dl =d+0.50 mm with tip clearance c2=*+0.50 mm.

2. Fitting Technique for Plastic Profiled SemiΓÇö Rigid Barriers No. 1 and No. 2 referenced under 1. The barriers are designed for installation into horizontally cut walls of civil engineering structures damaged by moisture. The wet wall, the thickness of which is denoted t, is mechanically cut at the accurately set level corresponding to the target height of barrier insertion. The cut of height CH is mechanically cleaned from debris and dust. While the wall is cut and cleaned, the Plastic Profiled Semi-Rigid Barriers No. 1 and No. 2 are prepared so that the initial length X of either Barrier No. 1 or Barrier No. 2 is reduced to the designed length DL (DL=L + 5 + 5 cm) and the initial height, h, of the fins, F, adjusted by precision grinding to the desired height, hi . The adjusted fin height, hi , should exceed the cut height, CH, for 0.20 mm (hl =h+0.20 mm). The wall cut is filled with cement-mortar slurry using a slurry injection pump. The mortar is CHARCTERIZED by additives (plasticizers and retarders) that improve plasticity and extend the wait-on-cement time. The product joints DEFINED as Plastic Profiled SemiΓÇö Rigid Barriers No. 1 and No. 2 are interlocked by way of their alternating male and female couplings. The barriers are interconnected and, by light hammering, inserted into the wall cut of height CH, filled with mortar slurry. Thus connected and fitted into the wa s, the barriers form an unbreakable and watertight impediment to capillary moisturizing. The invention as referred to in items 1 and 2 herein is SPECIFIC inasmuch as the Plastic Profiled SemiΓÇö Rigid Barriers No. 1 and No. 2 present a new postconstructional horizontal waterproofing system in which the difference in height, Ahl , between the fin height, h, and wall cut height, CH (Ahl =h-CH) prevents subsidence and fracturing of the treated walls or columns of the civil engineering structures.