33results about How to "Reduce early heat of hydration" patented technology

The invention discloses a method for producing a novel light-weight wall material by mixing coal slag. The coal slag produced by a thermal power plant replaces 20-100% of sand. On the one hand, the consumption of the sand is reduced, the production cost is lowered greatly, resources are saved, waste materials are recycled, and the environmental pollution is relieved. On the other hand, early hydration heat of concrete mixed with the coal slag is reduced, the sulfate resistance of the concrete is improved, and the impermeability has the direct bearing on the carbonization resistance, freezing resistance and erosion resistance of the concrete and further has an important effect on shrinkage and creepage of the concrete. In addition, the coal slag is lighter than the sand, so that the volumetric weight of the concrete mixed with the coal slag is reduced; a wall is light in deadweight; the mounting efficiency is improved; for mechanical properties, compression resistance and a suspension force of the light-weight wall material mixed with the coal slag are greatly higher than those of a light-weight wall material used for construction and produced by mixing no coal slag; and the method has very good economic and social benefits.

The invention discloses a slow hardening pump deliver type three expansion source concrete expansion agent, which is characterized by comprising preparation of raw materials such as anhydrite, high alumina chamotte, high-calcium sulphoaluminate chamotte, calcined magnesite and so on by weight portion and externally doped slushing agent, water retention agent, air entraining agent and retardant. The preparation method of the expansion agent comprises steps of crushing, common mixture, mixing and grinding and external doping mixture and finish product forming. The product has low alkali content, excellent expansion performance, strong suitability with concrete, balanced mechanical property after hardening, and small gradual slump loss of concrete shrinkage compensation, contributes to improving safety and durability of reinforced concrete, obviously improves the cracking resistance, volume stability, impermeability and frost resistance, and is simple and convenient to use and easy to control quality in construction. The slow hardening pump deliver type three expansion source concrete expansion agent can meet construction use requirements of commercial concrete, long distance pump-delivering concrete and mass concrete.

The invention discloses a method for designing the mixing ratio of machine-made sand self-compacting lightweight aggregate concrete. The method includes: (1) determining the water-cement ratio according to the configuration strength, and determining the unilateral consumption of each raw material in the clean slurry in combination with the improved water consumption formula; 2) Determine the unilateral amount of lightweight aggregate and machine-made sand according to the value of primary slump expansion; convert the initial amount of each raw material into a preliminary benchmark mix ratio; (3) use the orthogonal test method to optimize the amount of each raw material to obtain the benchmark mix ratio (4) Convert the base mixing ratio to the production mixing ratio according to the raw material index. The present invention fully considers the characteristics of machine-made sand and lightweight aggregate, improves the water consumption formula, and proposes an additional water consumption correction factor for machine-made sand γ 2 , and give the value range. Pre-wet the lightweight aggregate with additional water, and add a large amount of fly ash and some silica fume and other mineral admixtures, which can effectively inhibit the floating of the lightweight aggregate and ensure the working performance of the machine-made sand self-compacting lightweight aggregate concrete and mechanical properties.

The invention provides a salt erosion-resistant concrete and a preparation method thereof, belonging to the field of concrete. The salt erosion-resistant concrete provided by the present invention comprises the following components in parts by mass: 570-600 parts of cement, 1100-1106 parts of gravel, 640-665 parts of sand, 25.5-26 parts of nanoclay, and 0.32-0.35 parts of water reducer 0.02-0.04 parts of thickener, 0.23-0.27 parts of defoamer, 0.35-0.42 parts of air-entraining agent, and 185-240 parts of water. The invention effectively improves the pore structure inside the concrete by adding the nano-clay, the incorporation of the nano-clay reduces the corrosion of the concrete to chloride and sulfate, and prolongs the service life of the concrete. The results of the examples show that the salt erosion-resistant concrete provided by the invention can effectively resist the erosion of chloride salts and sulfates.

The present invention discloses a cement concrete for the wet connection seam of a system sequentially comprising simply-supported bridge and continuous bridge, and a preparation method thereof, wherein the cement concrete comprises cement, river sand, water, a polycarboxylic acid-based efficient water reducer, rice hull ash, apatite, sericite, sepiolite, a sodium polyacrylate high water absorption resin, talc powder, nanometer calcium carbonate, polyethylene fibers and polyester fibers, and with the synergistic effect among the mineral components such as the apatite, the sericite and the sepiolite and the two fibers, the toughening can be achieved, the impact resistance and the extension ability of the concrete can be improved, and the problems that the wet connection seam concrete is damaged and the bridge surface cracks can be effectively solved. According to the present invention, the cement concrete has advantages of high compressive strength, good toughness, impact resistance, permeation resistance, self-leveling, and the like.

The invention discloses a secondary ettringite type expanding agent and a preparation method and application thereof. The preparation method comprises the following steps of: stirring a pozzolanic material, a calcium material, plaster and water, forming into a blank or spheres, naturally curing, performing dry heating curing in a curing cell for 0.5 to 10 hours, raising the temperature to 100-170DEG C, and keeping the temperature for 0.5 to 10 hours for dehydration and ettringite decomposition reaction, or standing the formed blank or spheres for 2 to 10 hours, curing under steam pressure, and dehydrating for 0.5 to 10 hours, or dehydrating the thermally synthesized aluminosilicate material and wastes thereof at the temperature of higher than 100DEG C for 0.5 to 10 hours; and mixing and grinding 60 to 95 weight parts of material and 5 to 40 weight parts of anhydrous gypsum, or respectively grinding 60 to 95 weight parts of material and 5 to 40 weight parts of anhydrous gypsum and uniformly mixing to obtain powder of which the specific surface area is more than 200m<2> / kg, namely the secondary ettringite type expanding agent. The secondary ettringite type expanding agent can endow mortar and concrete with micro-expansion property, and improve the volume stability of the mortar and concrete.