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.

The use of branched copolymers of the general structure (I) as additives for increasing the flow rate and for reducing the viscosity of mineral binder compositions. Further, mineral binder compositions including at least one branched copolymer of the general structure (I):

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It is disclosed the use of amorphous silica reagent produced from serpentine as pozzolane additive material, and more particularly a concrete mixture, such as high performance and ultra-high performance concrete, comprising a hydraulic binder; sand; aggregates, chemical admixture, mineral admixture as silica fume and an amorphous silica reagent (AmSR), wherein the AmSR is admixed for example with General Use Portland Cement and provides synergistic effect when combined with silica fume.

Compositions and a method for making self consolidating grouts containing fly ash, ground granulated blast slag, and lime are described. No polymeric admixtures are utilized, and the 28 day cure strength of the cured gouts exceeds the minimum ASTM standards. The uncured grout exhibits slump flows between 24 and 30″ without visible segregation of the components.

A low-density, high-strength concrete composition that is both self-compacting and lightweight, 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 an oven-dried density as low as 40 lbs./cu.ft. The concrete, at the density ordinarily found in structural lightweight concrete, has a higher strength and, at the strength ordinarily found in structural lightweight concrete, a lower density. 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.

The invention relates to use of nano-fibrillar cellulose as an gas-entrainment stabilizer, which when used in cementitious materials, provides improved gas pore structure quality and/or stability and/or robustness with regard to water content variation. The invention further relates to a method for stabilizing gasentrainment of cementitious materials and to a method for providing cementitious material with improved air pore structure quality and/or stability and/or robustness with regard to water content variation.

A concrete mix, including: cementitious content between 25 and 200 kg/m.sup.3; fly ash content between 25 and 175 kg/m.sup.3; dirty sand with fine aggregates between 3% and 20%; water content between 150 I/m.sup.3 and 250 l/m.sup.3; and a chemical admixture comprising one or more components selected from the following: an acrylic, formaldehyde-free polymer-based admixture, modified in aqueous solution; a surfactant admixture configured to entrain micro air bubbles in concrete; and an organic polymer comprising hydrophilic groups for increasing the viscosity of the mixture.

The present invention relates to very high workable yet controllable concrete mix design, admixture composition, and process for placing concrete. The mix design relates to particular aggregate/cement ratios and types which are characteristic of ready mix concrete (RMC), which provide high fluidity reminiscent of self-consolidating concrete (SCC), and which provides advantages over both RMC and SCC in terms of ease and speed in placement and finishability at the construction site placement zone, regardless of whether into a horizontal formwork (e.g., for slabs, floors) or into vertical formwork (e.g., for blocks, walls, columns, etc.), without loss of control and without generating high risks of segregation even when small amounts of water are added at the size to facilitate finishing of the concrete surface. An inventive admixture combination which enables this unique design involves two different polycarboxylate comb polymers in combination with two specific viscosity modifying agents, and this combination provides highly workable concrete to be placed in a controlled, efficient manner.

An object of the present invention is to provide a method for constructing a base course without rolling compaction, in which a compacting step by rolling compaction and further adjustment of the water content of the mixture to the optimum water content are not necessary, and to provide a mixture for base course, which enables the said method. The above object is attained by providing a method for constructing a base course without rolling compaction, which comprises a step of obtaining a mixture by mixing an aggregate, an asphalt emulsion, and a cement, wherein the mixture is in a high-water-content state in which a water content of the mixture is above an optimum water content of the aggregate, and a step of spreading the mixture; and which does not comprise a step of rolling compaction, and by providing a mixture for a base course, comprising an aggregate, an asphalt emulsion, and a cement, wherein the mixture is in a high-water-content state in which a water content of the mixture is above an optimum water content of the aggregate.

A controlled low strength material has constituents that include a cement, an aggregate, a heavy oil fly ash, and a water. The controlled low strength material has a compressive strength in a range of 300 kPa to 2.1 MPa. In certain embodiments, the heavy oil fly ash can be part of a heavy oil fly ash slurry.