摘要:
In the present invention copolymers of certain ethers and olefinic mono- acids (or salts or in some cases esters thereof) have been discovered to be effective superplasticizers for hydraulic cements. When admixed into wet cement compositions these polymeric compounds give the cement mixture higher slump and lower slumploss over time. Alternatively, the copolymers of this invention may be used in preparing a cement mixture requiring less water, to yield a hardened cement with greater compressive strength.
摘要:
Compositions and methods for increasing grinding efficiency of cement, cement clinker, raw materials for cement, and other inorganic particles. Use of biomass-derived polyols such as diols, triols, or mixtures thereof, optionally with a conventional grinding aid, cement quality improver, and/or hexavalent chromium reducer, are believed to provide less risk of sludging when compared to glycerides obtained from fossils fuel sources.
摘要:
Compositions and methods for increasing grinding efficiency of cement, cement clinker, raw materials for cement, and other inorganic particles. Use of biomass-derived polyols such as diols, triols, or mixtures thereof, optionally with a conventional grinding aid, cement quality improver, and/or hexavalent chromium reducer, are believed to provide less risk of sludging when compared to glycerides obtained from fossils fuel sources.
摘要:
An additive for hydraulic cement compositions is provided which advantageously provides corrosion inhibition and set acceleration, in combination with a high level of fluidity and retention of fluidity over a desired period of time. The cement additive comprises an accelerator selected from the group consisting of alkali or alkaline earth metal nitrates, alkali or alkaline earth metal nitrites, and mixtures thereof, and a plasticizer comprising copolymers of an ether comonomer and an ethylenically-unsaturated comonomer. Fluid hydraulic cement compositions and a method of preparing them are further provided comprising these additive combinations.
摘要:
Methods and compositions involving the use of nitrogen-containing coordinated metal compounds for stabilizing chromium VI reducing metal cations, Exemplary uses include processes for making cement, and exemplary compositions include cement additives, concrete admixtures, as well as hydratable cement and cementitous compositions.
摘要:
New set-accelerating admixtures for hydraulic cement compositions are disclosed. These admixtures incorporate set-accelerating compounds and methylol derivatives of amino acids, are found to be surprisingly effective in decreasing the initial set time of hydraulic cements, mortars, and concretes, and are particularly advantageous in reduced-temperature set-accelerators.
摘要:
An association complex formed in a liquid environment from a metal-based chromium (VI) reducer and a non-lignosulfonate-based complexing agent is introduced into cement clinker or hydratable cement particles. In preferred embodiments, the formation of the association complex provides storage stability to the chromium reducer within the cement, such that the level of chromium (VI) after water is added to the cement remains less than 2 ppm for certain duration after mixing with water and without the necessity for further additions of chromium reducer during said duration (e.g., 26-84 or more days after addition). Compositions having the association complex are also described.
摘要:
A chromium VI reducing composition comprising particles of solid material selected from the group consisting of iron sulfate, the particles being substantially uniformly dispersed within a liquid carrier, the liquid carrier further comprising a diutan or xanthan polysaccharide. Methods for modifying hydratable cementitious materials using the chromium reducing composition are also disclosed and provide advantages over dry powder or dissolved forms of sulfate compositions when used in cement manufacturing.