Efflorescence resistance of concrete blocks is enhanced through the use of glass powder in the concrete composition. The glass powder permits a reduction in the cement content; the glass powder also creates a pozzolanic reaction to change the free calcium ions in calcium hydroxide to calcium silicate to fix the calcium ions inside concrete. The composition includes cementitious binding material of ordinary Portland cement, fly ash, calcium sulfoaluminate cement, ground-granulated blast-furnace slag in an amount from 20 to 25 wt. %. Coarse aggregate is provided from 10 to 15 wt. percent. Fine aggregate is from 32 to 39 wt. %. The composition further includes glass powder having a diameter of less than approximately 75 microns in an amount from 17 to 23 wt. %. Water is present in an amount from 6 to 9 wt. %. The dry density of formed paving blocks is 1800-2200 kg/m.sup.3.

This invention provides in one aspect compositions that improve the corrosion-resistance of cementitious materials. In certain embodiments, the compositions of the invention inhibit the growth of acidophilic bacteria thriving in/on cementitious material.

Novel cement, concrete, mortar and grout embodiments for construction. The materials are produced through SCM and quicklime aqueous cement formation reactions. A novel cement is also presented that can be used to form improved concrete, mortar and grout placements. Several novel concrete embodiments are presented that can be used with any aggregate, and for any construction application; including saltwater marine placements.

Novel cement, concrete, mortar and grout embodiments for construction. The materials are produced through SCM and quicklime aqueous cement formation reactions. A novel cement is also presented that can be used to form improved concrete, mortar and grout placements. Several novel concrete embodiments are presented that can be used with any aggregate, and for any construction application; including saltwater marine placements.

The present application discloses a polyhydroxy aromatic intermediate, preparation thereof and use thereof in a polycondensate water-reducer with branched side chains. The polycondensate water-reducer with branched side chains has a branched side chain structure which provides a stronger steric hindrance. The synergistic effect of the branched side chains and the rigid skeleton of the aromatic ring greatly improves the water-reducing ability. Especially under a condition of low water/cement ratio, the improvement in water-reducing ability is more obvious. The branched polyether side chain is more conducive to the formation of a thicker water film layer, which has an obvious viscosity reduction effect. The conformation of the branched polyether side chain is less affected by different ionic environments in the pore solution in cement, and thus has a stronger adaptability to various raw materials. The water-reducer is suitable for the preparation of high-strength concrete, self-compacting concrete and concrete with low water-to-binder ratio and high volume of mineral admixtures, especially for the preparation of concrete containing machine-made sand.

A method for making a low cost, lightweight carbon aggregate from coal at, above, or below atmospheric pressure, and a lightweight concrete composition utilizing the lightweight carbon aggregate is described.

A method for making a low cost, lightweight carbon aggregate from coal at, above, or below atmospheric pressure, and a lightweight concrete composition utilizing the lightweight carbon aggregate is described.

The present invention provides for a compressible grout mix for filling an annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation and a method of filling the annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation utilizing the compressible grout mix for resilient absorption of forces in the hardened state of the compressible grout mix exerted by the time dependent deformation of the rock wall surface into the tunnel opening. The method includes:

a. providing the compressible grout mix comprising hydraulic binding agent, bentonite clay, polymer foam particles, water-reducing admixture, water and air,

b. placing the compressible grout mix in the annular gap between the tunnel wall rock surface and the tunnel liner, and

c. allowing the compressible grout mix to set, wherein the compressible grout mix in the hardened state has a compressible ratio greater than the anticipated time dependent deformation.

The present invention provides for a compressible grout mix for filling an annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation and a method of filling the annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation utilizing the compressible grout mix for resilient absorption of forces in the hardened state of the compressible grout mix exerted by the time dependent deformation of the rock wall surface into the tunnel opening. The method includes:

a. providing the compressible grout mix comprising hydraulic binding agent, bentonite clay, polymer foam particles, water-reducing admixture, water and air,

b. placing the compressible grout mix in the annular gap between the tunnel wall rock surface and the tunnel liner, and

c. allowing the compressible grout mix to set, wherein the compressible grout mix in the hardened state has a compressible ratio greater than the anticipated time dependent deformation.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement: SF:NP in the cementitious blend composition lies in the range of (24-63): (5-44): (32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.