A method of making a structural lightweight and thermal insulating concrete is described. The concrete has a coarse aggregate partly replaced by recycled plastic pieces. This enables the concrete to maintain a high compressive strength, low thermal conductivity, and low weight, while providing a use for waste plastic. The waste plastic pieces may comprise polyethylene in the form of flakes, fibers, or granules. Due to its low unit weight, adequate compressive strength and high thermal resistance the developed concrete can be used as a structural lightweight and thermal insulating concrete. The use of this concrete leads to economic and environmental benefits.

A method of designing a cement composition may include: minimizing an objective function subject to a plurality of constraints to produce a cement composition including at least one cement component and water; and preparing the cement composition.

Disclosed are a method for separately preparing light magnesium oxide and calcium oxide by using dolomite and an application thereof in preparation of a calcium-magnesium composite expanding agent. In the method for preparing light magnesium oxide and calcium oxide, based on the difference in decomposition temperature between magnesium carbonate and calcium carbonate during the calcination and decomposition of dolomite and the difference in the weight of the materials after decomposition, the effective separation of magnesium oxide and calcium oxide is realized by a one-step method, thus separately preparing light magnesium oxide and light calcium oxide. The calcium-magnesium composite expanding agent is prepared by using the foregoing light magnesium oxide and calcium oxide. On the one hand, the present invention solves the problem of the limited origin of the light magnesium oxide raw material of the magnesium expanding component in the calcium-magnesium composite expanding agent.

A phosphogypsum non-sintered ceramsite light aggregate composed of water and a mixture composed of phosphogypsum, mineral powder and cement. Raw materials of the mixture have weight percentages of phosphogypsum 80-90%, mineral powder 3.3-10%, cement 6.5-10%; the water has a weight of 17% of the total weight of the mixture. A method of preparing the phosphogypsum non-sintered ceramsite light aggregate. The phosphogypsum non-sintered ceramsite light aggregate is prepared by modification, granulation, curing, crushing, sieving and other processes by using phosphogypsum as a main material, cement as an alkaline activator, mineral powder as an active material.

A phosphogypsum non-sintered ceramsite light aggregate composed of water and a mixture composed of phosphogypsum, mineral powder and cement. Raw materials of the mixture have weight percentages of phosphogypsum 80-90%, mineral powder 3.3-10%, cement 6.5-10%; the water has a weight of 17% of the total weight of the mixture. A method of preparing the phosphogypsum non-sintered ceramsite light aggregate. The phosphogypsum non-sintered ceramsite light aggregate is prepared by modification, granulation, curing, crushing, sieving and other processes by using phosphogypsum as a main material, cement as an alkaline activator, mineral powder as an active material.

The present invention relates to a composition in the form of a mixture comprising F-type fly ash, a reactive silicon source, a setting accelerator and a light aggregate with a density of less than 900 kg/m.sup.3 and a mechanical strength of at least 0.08 MPa, and the uses thereof to obtain light and fireproof construction materials.

A low-density, high-strength concrete composition that is lightweight and self-compacting or non-self-compacting, with a low weight-fraction of aggregate to total dry raw materials, and a highly-homogenous distribution of a non-absorptive and closed-cell lightweight aggregate such as glass microspheres or copolymer polymer beads or a combination thereof, and the steps of providing the composition or components. Lightweight concretes formed therefrom have low density, high strength-to-weight ratios, and high R-value. The concrete has strength similar to that ordinarily found in structural lightweight concrete but at a lower density, such as an oven-dried density as low as 40 lbs./cu.ft. Such strength-to-density ratios range approximately from above 30 cu.ft/sq.in. to above 110 cu.ft/sq.in., with a 28-day compressive strength ranging from about 3400 to 8000 psi.

A geopolymer cement and a method of producing the same are provided. A geopolymer cement binder may be provided including a geopolymer precursor and magnesium oxide as an alkali activator. The geopolymer cement binder may be mixed with water using high shear mixing.

A method of cementing may include preparing a cement composition comprising water, a hydraulic cement, and an agglomerated zeolite catalyst; placing the cement composition in a wellbore.

A fiber cement material formulation comprising a cementitious binder, a siliceous material, fiber, alumina trihydrate and a bifunctional low density additive wherein the bifunctional low density additive comprises any one or more of diatomaceous earth, recycled autoclave fiber cement dust or cellulose dust. The fiber cement material formulation optionally further comprises a secondary low density additive which may be perlite. In some embodiments, a fiber cement article manufactured from the fiber cement material formulation comprises a density of approximately 1.1 g/cm.sup.3 or below.