Natural marble with its elegant, luxurious wear resistance and corrosion resistance, a large number of modern construction projects. Attach importance to natural marble quality common causes and quality control. Making and improving construction technology are practical and theoretical problems in engineering quality management.
Dali stone installation and construction process common quality problems and reasons
1.1 The marble wall is hollow and falling off
The main reasons for this phenomenon are water seepage at the base or matrix and insufficient grouting; On the other hand, marble contains CaCO3 and a variety of mineral materials and. Other impurities, exposed to wind, frost, rain, snow and sun for a long time, can cause its discoloration.
The CaCO3 in marble and the acid kind substance in the air meet to produce chemical reaction, generate the gypsum that dissolve easily in water, make its surface lose luster and rough, straight cause to appear pitting spot crack and fall off.
1.2 plate joints are not straight, plate surface texture is not smooth
The main reasons are improper treatment of the base or matrix, there are local concave and convex surface; The finished plate is not strictly selected, the design and color are different, the specifications are not correct, and there are cracks, pollution and damage; No test number is given before installation; The height of stratified grouting is too high; The construction sequence is improper, etc.
1.3 Cracking of marble veneer
The main reason is that when the marble plate is inlaid on the outer wall or close to the kitchen, bathroom and other wet space parts, the installation is rough, the grouting of the plate joint is not strict, the erosion and the moisture gas penetrate into the plate joint, so that the metal connector is corroded and expanded, and the Dali stone is cracked by deformation thrust;
When the color of the dark seam or other hidden defects of the Dali stone, due to the structural settlement of stress concentration, resulting in the stone at the weak cracking; When vertical veneer, the upper and lower gap is small, the structure is deformed under pressure, and the plate is cracked by vertical pressure.
1.4 The marble veneer is damaged and contaminated
The main reason is the problem of site management, improper operation in the process of transportation, storage and warehousing of plates; The residual mortar is not immediately removed in the construction process; The construction site protection work is not done well after the installation.
Preparation for construction and installation of natural marble materials
2.1 Preparation of inserts
First of all, according to the design drawings to check the actual deviation of the structure, check the vertical leveling of the matrix wall, the larger deviation should be picked or repaired; Secondly, the actual height of the cylinder construction should be determined first, the center line of the column, as well as the upper and lower horizontal lines between the columns, to determine the size of the decorative panel block;
For the stair dado and the complex shape of the one-sided should be the first solid side, if necessary, with other materials to put full size proofing. Finally, according to the measured specifications and sizes of the wall column, and the width of the joints between the decorative panels is calculated, the plates are calculated, numbered according to the installation sequence, and the block and node drawings are drawn, which are used as the basis for processing and ordering.
2.2 Treatment of mounting surface and leveling
First of all, the construction matrix or base has enough stability and stiffness, so that the surface is smooth but rough. The smooth surface should be wool first, the depth of chisel hair is 5~15mm, and the spacing is >15mm. Mortar, dust, oil and other residues on the surface of the substrate or base must be cleaned with a steel wire brush and then rinsed with clean water. When the pillar is inlaid with Dali stone, it should pop out the center line of the column and the elevation line of the horizontal line according to the size of the building axis, and take this as the leveling datum.
2.3 Stone inspection and numbering
Stone after the package is strictly selected varieties specifications consistent color edge off. Angular sheet; Then according to the design size of the trial assembly, set square grinding edge, check the flatness and measure the verticality of the corner, so that the size in line with the design requirements, control the actual size of the inlaid, to ensure that the width and height of the same; Color changes to be natural, with a wall or facade tone to be unified.
When spelling the pattern, try to make the upper and lower right and left smooth coordination, natural texture, the same surface pattern should be symmetrical, so as to achieve one integrated whole; Pre-spell number, to the inlaid part, to strictly select the stone, the texture of the good color and lustre of the board used in the main space.
Improvement of natural marble stone construction
Art of the traditional natural Dali stone shop paste technology, is on the base of the pre - hanging steel net wire binding and then pouring mortar. This process is cumbersome and complicated, and the cost is high. In engineering, it often causes quality problems such as poor adhesion and uneven surface due to improper grasp.
Improved technology is a new construction technology which is based on absorbing foreign advanced technology and combining the advantages of traditional technology. The method of plate numbering and pattern matching for construction preparation of this process is basically the same as the traditional process. Other technical points are as follows:
3.1 Substrate treatment
First of all, wet the substrate which is cleaned in advance with water, spread 1:1 cement mortar, use coarse sand or medium sand, and scrub the back of the stone with water to enhance the bonding force;
3.2 Plate drilling
At each end of the 1/4 edge away from the plate with electric drill drilling, hole depth 35~40mm, aperture 6mm. When the plate width is less than 500mm, the number of holes is 2; When the plate width >500mm, the number of holes is 3;
When the plate width is >800mm, the number of holes is 4. Then, a straight hole is drilled on both sides of the plate respectively. The hole location is 100mm away from the lower end of the plate, the aperture is 6mm, and the depth of the hole is 35-40mm. The length and width of the upper and lower straight holes should be no less than 70cm and 30cm respectively, and the distance from the edge of the plate should be no less than 100cm.
In order to make the new and old concrete closely combined, grooving interface chisel hair cleaning, gang fiber coagulation. Soil can be improved a grade, that is, the use of C35 extra fine sand steel fiber concrete.
3.3 Permeable cracks
Such cracks are mostly structural stress cracks. Whether the roadbed and grass-roots level are stable should be determined before repair. Only after the foundation reaches enough stability can it be repaired.
Slot in the form of chiseling or the whole plate renovation, after repeated tests using mixing (on page 219) with alloy chisel on the back of the chisel, 6~8mm deep, in order to install U shaped nails.
3.4 Matrix drilling
After the plate is drilled, it shall be divided into blocks according to the base line and put into place temporarily. On the corresponding matrix position of the upper and lower straight holes of the plate, the impact electric drill is used to drill the inclined hole equal to the number of holes in the plate. The hole inclination is 45°, the aperture is 6mm, and the hole depth is 40~50mm.