Abstract: A controlled low strength material has constituents that include a cement, an aggregate, and a water. The aggregate includes concrete demolition waste. The controlled low strength material has a compressive strength that does not exceed 8.3 MPa, measured at 28 days. The controlled low strength material can alternately include a heavy oil fuel ash and the controlled low strength material can have a compressive strength that does not exceed 2.10 MPa, measured at 28 days.

Abstract: 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.

Abstract: A nanozeolite modified green concrete contains alkali-activated natural pozzolan. Natural pozzolan is a green and sustainable material, potentially useful in green concrete, e.g., to curb greenhouse gas emissions associated with ordinary Portland cement production. Nanozeolite (NZ) is present as an additive to the green concrete, e.g., at 3 to 5 wt. %, of natural pozzolan to improve strength development and microstructural properties, resulting in superior strength and denser microstructure compared to a green concrete without nanozeolite.

Abstract: A nanozeolite modified green concrete contains alkali-activated natural pozzolan. Natural pozzolan is a green and sustainable material, potentially useful in green concrete, e.g., to curb greenhouse gas emissions associated with ordinary Portland cement production. Nanozeolite (NZ) is present as an additive to the green concrete, e.g., at 3 to 5 wt. %, of natural pozzolan to improve strength development and microstructural properties, resulting in superior strength and denser microstructure compared to a green concrete without nanozeolite.

Abstract: A lightweight structural concrete formulation comprises a wet mix of about 460 kg/m3 of cementitious material such as ordinary Portland cement of which about 50 percent has been replaced by ground granulated basic furnace slag (GGBFS) and 7 percent by silica fume (SF) in other words the mix introduces between about 178 and 228 kg/m3 therefore the combination is good to produce secondary reaction products when the cement hydrates which produces secondary calcium silicate hydrate (C—S—H) which makes the structure dense and thereby increases its mechanical durability characteristics of the concrete product. Possible ratios of GGBFS and SF are 30-70 percent and 5-10 percent, respectively. By making the structures dense increases the mechanical and durability characteristics of the concrete product. Other ratios have been made including GGBFS of 30-70 percent and silica fume 5-10 percent, respectively.

Abstract: A heavyweight concrete composition comprising cement, steel slag coarse particles, steel slag fine particles, and iron ore aggregate, a wet concrete slurry of water mixed with the heavyweight concrete composition, and a heavyweight concrete which is a cured form of the wet concrete slurry. In the present disclosure, sand, which is used in conventional concretes, is replaced with steel slag fine particles to produce a sand-free heavyweight concrete.

Abstract: The present invention discusses methods for making a cement composition comprising a nanoparticle zeolite. The addition of the nanoparticle zeolite may provide enhanced compressive and tensile strengths, improved rheology, and a change to the cement microstructure. These effects may improve the cement's use as a cement sheath in drilling operations and under high pressure and high temperature (HPHT) conditions.

Abstract: The present invention discusses methods for making a cement composition comprising a nanoparticle zeolite. The addition of the nanoparticle zeolite may provide enhanced compressive and tensile strengths, improved rheology, and a change to the cement microstructure. These effects may improve the cement's use as a cement sheath in drilling operations and under high pressure and high temperature (HPHT) conditions.

Abstract: The present invention discusses methods for making a cement composition comprising a nanoparticle zeolite. The addition of the nanoparticle zeolite may provide enhanced compressive and tensile strengths, improved rheology, and a change to the cement microstructure. These effects may improve the cement's use as a cement sheath in drilling operations and under high pressure and high temperature (HPHT) conditions.

Abstract: A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.

Abstract: A lightweight structural concrete formulation comprises a wet mix of about 460 kg/m3 of cementitious material such as ordinary Portland cement of which about 50 percent has been replaced by ground granulated basic furnace slag (GGBFS) and 7 percent by silica fume (SF) in other words the mix introduces between about 178 and 228 kg/m3 therefore the combination is good to produce secondary reaction products when the cement hydrates which produces secondary calcium silicate hydrate (C-S-H) which makes the structure dense and thereby increases its mechanical durability characteristics of the concrete product. Possible ratios of GGBFS and SF are 30-70 percent and 5-10 percent, respectively. By making the structures dense increases the mechanical and durability characteristics of the concrete product. Other ratios have been made including GGBFS of 30-70 percent and silica fume 5-10 percent, respectively.

Abstract: A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.

Abstract: A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.

Abstract: A cement slurry composition, containing hydraulic cement, water, and from 1 to less than 4% of an organically modified nanoclay. A method for cementing a high pressure high temperature well by pumping the cement composition of claim 1 between a casing and a formation of a well bore to fill a gap between the casing and the formation, and allowing the cement to harden.

Abstract: The Portland cement type-G with nanosilica additive for high pressure-high temperature applications is a mixture of about 1.0%-2.0% by dry weight of nanoparticles of hydrophilic silica, with type-G Portland cement (and other admixtures) forming the balance of the mixture. The cement so formed is suitable for use in deep petroleum wells, which require cement that can be introduced under high temperature (about 290° F.) and high pressure (about 8,000-9,000 PSI) conditions. The addition of hydrophilic nanosilica shortens the thickening time for the cement slurry and causes a growth in the average compressive strength of the cement. In addition, the hydrophilic nanosilica does not cause any free water separation from the cement slurry column after aging.

Abstract: The Portland Saudi cement type-G with nanosilica additive for high pressure-high temperature applications comprises a mixture of about 1.0%-2.0% by dry weight of nanoparticles of silica; and type-G Portland Saudi cement forming the balance of the mixture. The cement so formed is suitable for use in deep petroleum wells, which require cement that can be introduced under high temperature (about 290° F.) and high pressure (about 8,000-9,000 psi) conditions. The addition of nanosilica shortened the thickening time for the cement slurry and caused a growth in the average compressive strength of the cement samples. In addition, the nanosilica did not cause any free water separation from the cement slurry column after aging.

Abstract: The strut and tie method for waffle slabs relates to computer modeling of waffle slabs to predict strength and mode of failure. The waffle slab strut and tie method utilizes a three-dimensional strut-and-tie model, which is applied to distinct structural features of waffle slabs. Individual ribs in the slab form two-dimensional trusses, which are connected with perpendicular trusses at rib intersections. The geometry of the slab defines the location of nodes for finite element analysis.

Abstract: The strut and tie method for waffle slabs relates to computer modeling of waffle slabs to predict strength and mode of failure. The waffle slab strut and tie method utilizes a three-dimensional strut-and-tie model, which is applied to distinct structural features of waffle slabs. Individual ribs in the slab form two-dimensional trusses, which are connected with perpendicular trusses at rib intersections. The geometry of the slab defines the location of nodes for finite element analysis.