Lactate activated cement and activator compositions

Abstract

Cementitious compositions in which the cementitious properties of fly ash are carefully controlled are described. The cementitious compositions may be substantially free harsh acids and bases such as citric acids (≈pH 2.2) and alkali metal activators including alkali hydroxides (≈pH 12-14) and metal carbonates (≈pH 11.6). The use of these harsh chemicals creates acid base reactions during use of the products. Instead of these harsh chemicals, a lactic acid salt based activator is be used as a reaction accelerator. Boric compounds may be used as a retarder in the compositions.

1 - 29 . (canceled) 
     
     
         30 . An activator composition for pozzolanic cement comprising:
 a chemical activator based on lactic acid comprising more than 50% by weight of the total weight of activators in the activator composition; and   a chemical retarder.   
     
     
         31 . The activator composition of  claim 30 , wherein the chemical activator is a pH neutral salt of lactic acid. 
     
     
         32 . The activator composition of  claim 30 , wherein the chemical activator comprises potassium lactate, sodium lactate, lithium lactate, calcium lactate, or magnesium lactate. 
     
     
         33 . The activator composition of  claim 31 , wherein the pH neutral salt comprises an alkaline metal or alkaline earth. 
     
     
         34 . The activator composition of  claim 30 , wherein the chemical retarder comprises a boron compound. 
     
     
         35 . The activator composition of  claim 34 , wherein the boron compound is selected from the group consisting of boric acid, boric oxide, sodium borate, sodium tetraborate, potassium borate, potassium tetraborate, borax pentahydrate, and borax decahydrate. 
     
     
         36 . The activator composition of  claim 30 , wherein the chemical retarder is dissolved in the activator composition in a concentration between 0.1% and 40.0%. 
     
     
         37 . The activator composition of  claim 36 , wherein the chemical retarder is dissolved in the activator composition in a concentration between 0.1% and 30.0%. 
     
     
         38 . The activator composition of  claim 37 , wherein the chemical retarder is dissolved in the activator composition in a concentration between 10.0% and 30.0%. 
     
     
         39 . The activator composition of  claim 30 , wherein the activator composition is substantially free of citric acid activators, alkali metal activators, and metal carbonate activators. 
     
     
         40 . The activator composition of  claim 30 , wherein the chemical activator based on lactic acid comprises more than 75% by weight of the total weight of activators in the activator composition. 
     
     
         41 . The activator composition of  claim 40 , wherein the chemical activator based on lactic acid comprises more than 95% by weight of the total weight of activators in the activator composition. 
     
     
         42 . The activator composition of  claim 30 , wherein the pozzolanic cement is substantially free of Portland cement. 
     
     
         43 . The activator composition of  claim 30 , wherein the chemical activator based on lactate acid comprises a 60 wt. % solids solution of neutralized lactic acid.