The main technical performance indicators of cement: (1) Specific gravity and bulk density: The proportion of ordinary cement is 3:1, and the bulk density is usually 1300 kg/m3. (2) Fineness: refers to the thickness of cement particles. The finer the particles, the faster the hardening and the higher the early strength. (3) Condensation time: The time required for cement to add water to start coagulation is referred to as the initial setting time. The time required to complete the stirring from the addition of water is called the final setting time. The initial setting time of Portland cement is not earlier than 45 minutes and the final setting time is not later than 12 hours. (4) Strength: Cement strength should meet national standards. (5) Volume stability: refers to the uniform performance of cement volume change in the hardening process. The cement contains many impurities and will produce uneven deformation. (6) Heat of hydration: The effect of cement and water will produce an exothermic reaction. In the process of cement hardening, the constant release of heat is called heat of hydration. Commonly used cement labels: No. 25, No. 275, No. 325, No. 425, No. 525, No. 625, etc., whose tensile strength is different due to different varieties, and their labels are different. The MPa value is between 2.8-4.5 and 3.4-8.0. Decorative cement varieties: Decorative cement is commonly used to decorate the surface of buildings. It is simple in construction, convenient in shape, easy to maintain, and inexpensive. Cement mortar application and purchase In home decoration, cement mortar is used for floor tiles, wall tiles and masonry, etc. It not only enhances the adsorption capacity of the surface material and the base layer, but also protects the internal structure. At the same time, it can be used as a leveling layer for building rough surfaces. So in the renovation project, cement mortar is an essential material. Many customers believe that the greater the proportion of cement in the entire mortar, the stronger the adhesiveness, and therefore often disagree with the decoration company on the use of cement. In actual fact, in the case of paste tiles, if the cement number is too large, when the cement mortar condenses, the cement absorbs a large amount of water. At this time, the ceramic tile surface moisture is easily absorbed and cracked, shortening the service life. Cement mortar should generally be stirred at a ratio of cement:sand=1:2 (volume ratio). The principle of buying cement and sand: In order to ensure the quality of cement mortar, cement must be paid attention to whether or not the 425# Portland cement produced by Dachang is used in the purchase. Sand should be selected sand, the sand thickness of the particles is very suitable for use in cement mortar. Many customers think that the better the sand, the better the mortar is, in fact, a misunderstanding. Too fine sand adsorption capacity is not strong, can not produce a large friction and stick to the tile. Yellow sand cement purchase Xuanguan decoration study decoration cement decoration home decoration decoration company decoration find decoration company please tile price 1M Mini Measuring Tape,Small Retractable Tape Measure,Precision Tape Measure,Tape Measure Scale SHANGQIU CHAOYUE MEASURING TOOLS CO., LTD , https://www.equipmentool.com