摘要:
The present invention discloses compositions and methods wherein polycarboxylate comb polymers are used as grinding additives. The comb polymers contain a carbon-containing backbone and pendant groups wherein oxyalkylene pendant groups contain one or more ether linkage groups for providing robustness to the polymer for resisting degradation during grinding and hence sustaining workability and strength of hydratable cementitious materials, such as cements, pozzolans, limestone, and other cementitious materials.
摘要:
Methods and compositions of the invention involve the use of crude intermediate fermentation broth, derived from industrial glucose fermentation processes prior to completion of purification steps, as additives and admixtures for cementitious compositions.
摘要:
Methods and compostions of the invention involve the use of crude intermediate fermentation broth, derived from industrial glucose fermentation processes prior to completion of purification steps, as additives and admixtures for cementitious compositions.
摘要:
In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymer-containing plasticizer, or EO/PO comb polymer-containing plasticizer, and further containing clay, such as a smectite clay, which expands when in contact with water, the step of providing an agent operative to modify the clay whereby the plasticizer absorbing capability of the clay is reduced. In exemplary methods of the invention, the plasticizer is an EO/PO (e.g., oxyalkylene) plasticizer and preferably an EO/PO comb polymer, and the clay-activity-modifying agent may comprise an inorganic cation, an organic cation, a polar organic molecule capable of being absorbed by the clay, a clay dispersant (such as a polyphosphate), or a mixture thereof. For clay-activity-modifying agents which comprise a cation or a polar organic molecule, the agent is preferably added to the clay before water is introduced to the clay. For clay dispersant agents and some organic cations such as quaternary amines (which have a strong affinity for cationic exchange with the clay), the agent may be added before, during, or after water is introduced to the clay.
摘要:
The present invention relates to the use of polycationic compound in combination with a hydroxycarboxylic acid or salt thereof to enhance slump retention in cements and concretes having clay-bearing aggregates, wherein the clay otherwise absorbs or diminishes the dosage efficiency of polycarboxylate superplasticizers.
摘要:
An additive composition, a cement composition, and method for modifying rheology of an uncured masonry cement, comprising the use of at least one extra-cellular biopolymer, at least one anionic surfactant, and at least one cationic or amphoteric surfactant. Preferably, the biopolymer and surfactants are incorporated into the cement by incorporating the components into the grinding of clinker as part of the manufacture of the cement. Masonry cements produced by the invention have excellent workability, particularly when coarse sands are employed.
摘要:
The present invention discloses compositions and methods wherein polycarboxylate comb polymers are used as grinding additives. The comb polymers contain a carbon-containing backbone and pendant groups wherein oxyalkylene pendant groups contain one or more ether linkage groups for providing robustness to the polymer for resisting degradation during grinding and hence sustaining workability and strength of hydratable cementitious materials, such as cements, pozzolans, limestone, and other cementitious materials.
摘要:
Phosphate-containing polycarboxylate polymer dispersant compositions of the invention comprise a polymer made from polyoxyalkylene groups, acrylic acid groups, mono-ester groups, and optionally di-ester and tri-ester groups, all in specific molar ratios. The polymer dispersants of the invention achieve quick mix-in dispersibility, particularly within hydratable cementitious compositions such as concrete, in comparison with polycarboxylate polymer dispersants that do not contain phosphate groups, while having improved initial slump as well as slump retention compared to phosphate-containing polymers of the prior art.
摘要:
Exemplary compositions and methods for reducing hexavalent chromium in cementitious compositions involve the use of a liquid additive composition, comprising stannous chloride. Along with the stannous chloride may be used at least one co-additive comprising an antioxidant, oxygen scavenger, or mixture thereof, and/or at least one agent comprising a cement grinding aid, cement quality improver, or mixture thereof.
摘要:
Exemplary compositions comprise at least one aldopentonic acid, such as xylonic acid; and further comprise a lignin, a lignosulfonic acid or its salt, an additional sugar acid such as a aldohexonic acid or salt, a conventional admixture (such as a polyacrylate superplasticizer, a corrosion inhibitor, a set retard, a set accelerator, etc.), or a mixture thereof. Exemplary methods for obtaining microbiologically or enzymatically converted sugar acids are also described herein.