Several easily confused concepts of dry powder mortar

Hits:Published in:2018-06-25

Xingyang Mingzheng as one of engaged in building material equipment manufacturing and intelligent automatic control system development of large-scale professional enterprise, company produces all kinds of dry mortar mixing equipment excellent quality are both at home and abroad more than 100 countries and regions. Company production of dry powder mortar production line is a professional mixing and mixing equipment. Because our company not only provides mixing equipment and also provide raw material for the production of supplies. In this regard, many purchased company dry mortar production line equipment users also in my company to buy raw materials back to production, the dry powder mortar has been widely used, but in some customers provide the confusion in the production, use and supervision unit of dry mixed mortar some conception and performance of existing, mainly the following concepts:

1, viscosity and strength

The higher the viscosity, the higher the strength. Strength usually refers to the physical properties of the mortar after curing index, viscosity is usually refers to the state after the mixing of the mortar, is the construction of an indicator. There is no inevitable relationship between viscosity and strength. Factors affecting the strength of more, and viscosity is generally by adjusting the viscosity of cellulose ether, cellulose ether in hundreds of viscosity, up to a maximum of 2 00000 viscosity, cellulose ether according to the different uses of products to choose, the viscosity of cellulose and the strength is not necessarily relationship.

2, bond strength and compressive strength

Bond strength is the maximum bond strength of mortar on the bottom layer. There are two kinds of shear strength and tensile (tensile) strength. The tensile strength is the ability of the mortar surface to resist the tensile force acting on the surface of the surface.

Compressive strength is the maximum value when the mortar is destroyed by applying pressure, and it is generally the cohesive strength of the mortar. High bonding strength is not necessarily high compressive strength, low compressive strength is not necessarily low bond strength.

The two concepts are easy to engage in two aspects:The selection of additives. Concrete admixture (early strength agent, antifreeze, etc.) in the concrete test is only the test of compressive strength, such as anti freeze agent is to test the concrete in the low temperature resistance of the loss rate. Dry mortar products main test index is the bond strength, some of the mortar admixture in the choice should focus on considering bond strength, such as dry mortar special early strength agent mainly is refers to the bond strength of mortar early how to improve, rather than compressive strength increase how much. This point is very critical, according to our experience, some of the concrete adding agent directly to the mortar, mortar bond strength is very large, but play a negative role. The two is to judge the bond strength by compressive strength index. Ceramic tile adhesive mortar standards without compressive strength index requirements, and some people think ceramic tile adhesive mortar easily with hand thrust broken (compressive strength index) and that low bond strength. This is because the bonding property of the ceramic tile mortar can be improved by the addition of the polymer such as the re dispersible emulsion powder, but the compressive strength of the product can be reduced.

But there are exceptions: external wall insulation mortar flexibility index only the provisions of the pressure reduction ratio and does not specify the minimum value of compressive strength, but also bring some problems for practical application.

3, waterproof and water resistance

The concept of waterproof and water is mainly in the putty, water is a material in neutral water environment can not occur big changes, water is that water can not penetrate the. Just before the putty paint brush leveling material, does not have the performance should not have waterproof material. JG158 the putty for interior "and building JG157" building putty for exterior wall "standard only provides for the water resistance of the putty, putty forming after immersion in water for a certain period of time observation of putty layer is change. But in practical application process, some enterprises exaggerated propaganda, say own production of waterproof putty, and some use of units often ask putty for exterior wall is waterproof.

4, heat preservation and heat insulation

Heat preservation is the material or product of masonry walls to prevent heat loss and maintain the ability to stabilize at room temperature. Usually refers to the enclosure structure (including the roof, walls, doors and windows, etc.) in the winter to prevent the heat from indoor to outdoor, so that the ability to maintain the temperature of the room. Heat insulation refers to the material or products of the masonry wall to prevent heat from passing into the summer, to maintain the ability to stabilize at room temperature. Usually refers to the structure of the enclosure in the summer to isolate from the solar radiation heat and outdoor high temperature effect, so that the inner surface of the ability to maintain appropriate temperature.

The difference between heat preservation and heat insulation

(1) the heat transfer process is different.

Insulation is refers to the heat transfer process in winter, usually in steady heat to consider, taking into account some of the effects of unsteady heat transfer; thermal insulation is refers to the heat transfer process in the summer, usually to 24h for periodic heat transfer to consider.

(2) the evaluation indexes are different.

The insulation performance of commonly used heat transfer coefficient or heat transfer resistance evaluation. Insulation performance usually summer outdoor calculated temperature conditions (i.e. a hot weather) envelope internal surface, the temperature value to evaluate if under the same conditions the surface temperature is less than or equal to 240 mm thick brick wall (i.e. a brick wall) of the inner surface of the temperature is considered to comply with the requirement of heat insulation.

(3) different structural measures.

Due to the insulation performance was mainly determined on the size of the envelope structure heat transfer coefficient and the heat transfer resistance, by light porous thermal insulation material which is lightweight enclosure (for example color steel plate polystyrene or polyurethane foam sandwich roof panel and wall), the smaller heat transfer coefficient, heat transfer resistance is bigger, and the thermal insulation performance is excellent, but because of the quality of light, low thermal stability, easily influenced by solar radiation and indoor and outdoor temperature fluctuations, inner surface temperature to rise, so its thermal insulation is often poor.

Heat preservation performance is the heat transfer coefficient K value, K value, the smaller the better, the heat insulation is the thermal inertia index D value, D value and the greater the heat insulation performance is better. For example: the same thickness of EPS board and powder polystyrene particles, heat preservation performance (to calculate K value) is good effect of EPS, but heat-insulating property (calculated D value) is powder polystyrene particles.

5, hydrophobic and waterproof

"Term" definition of heat preservation material hydrophobic water test method ", the provisions for materials of resistance to water penetration of a performance index to reflect, have provisions, certain flows of water spray, specimen not permeable part of the volume percentage to represent. Hydrophobic water pressure is relatively small, waterproof material waterproof indicators are usually in the case of a certain dynamic water pressure test. Waterproof material is not necessarily a hydrophobic effect (water effect), water repellent material is not necessarily a good waterproof performance.

Above is Yingyang Mingzheng Xiaobian from engineer summary of dry powder mortar is easily confused with several problems, Xingyang Mingzheng production of dry mortar production line realized automatic production, investment industrial ideal, rational layout, greatly improve the production efficiency, customers!

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