Hydraulic and Portland cement products have a calcium silicate binder. They are used to plug leaks in concrete or masonry structures such as dams, culverts, water tanks, cisterns, swimming pools, mines, and sewer and water pipes. Hydraulic and Portland cement is also used with underground structures such as electric vaults and sewer access tunnels. are also used to build and repair underground structures such as electric vaults or sewer access tunnels. Some grades of hydraulic and Portland cement include aggregates and chemical additives to improve strength, entrain air, reduce heat generation and cracking, or improve corrosion resistance to sulphates and other chemicals.
Hydraulic and Portland cement differs in term of product type and setting or curing technology. Choices for product type include grouts, caulks, and fillers; coatings and thinset; concrete with coarse aggregates; cement-based liners and lining systems; mortars; and stock products available in particulate form. Choices for setting or curing technology include hydraulic, air, chemical, and heat setting; hot melt systems; and two-component or multi-component systems. Portland cement is a hydraulically-setting material that uses the hydration reaction of a salt to form a bond. Air setting or film drying materials harden through evaporation. Chemically-setting cements rely upon a chemical reaction process. Heat setting or thermoset products use elevated temperatures and/or pressures.
Processing specifications for hydraulic and Portland cement include set or cure time, set or cure temperature (with thermosetting systems), and maximum percentage of linear shrinkage. Thermal and mechanical specifications include maximum use temperature, flexural strength, and crushing strength. Flexural strength or cross-break strength is the maximum flexural stress that hydraulic and Portland cement can withstand before failure or fracture occurs. Compressive strength or crushing strength is the greatest compressive load per unit cross-section that products can withstand before mechanical failure or breakage occurs.
Hydraulic and Portland cement differs in terms of bonds, application and features. In addition to polymer-modified cement, hydraulic and Portland cement products may use acrylate, epoxy, polyurethane, vinyl ester or polyester bonds. Applications include glass and ceramics manufacturing, chemical and material processing, foundry work and metal processing, building and construction, wall and flooring, and structural components. In terms of features, some hydraulic and Portland cement is castable, fiber-reinforced, or suitable for use with gunning, ramming, or patching techniques. Waterproof and underwater-setting hydraulic and Portland cement is also available.