Methods of forming cured composite materials with optimized ph and related compositions and systems

Abstract

A method of producing a carbonated composite material includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less.

1 .- 20 . (canceled) 
     
     
         21 . A calcium silicate composition comprising solid components and liquid components;
 wherein the solid components comprise cementitious material in an amount of 8-25% by weight, based on the total weight of the solid components, and the remainder of the solid components are aggregate; and   wherein the liquid components comprise a pH enhancer in an amount of 20-50 ml/kg of the cementitious material, and water in an amount of 200-700 ml/kg of the cementitious material.   
     
     
         22 . The calcium silicate composition of  claim 21 , wherein the aggregate comprises first relatively large aggregate, and a second relatively small aggregate. 
     
     
         23 . The calcium silicate composition of  claim 21 , wherein the cementitious material comprises a calcium silicate compound in an amount of at least 50% by weight based on the total weight of the cementitious material, and ordinary portland cement. 
     
     
         24 . The calcium silicate composition of  claim 23 , wherein the cementitious material further comprises vitreous calcium alumino silicate. 
     
     
         25 . The calcium silicate composition of  claim 23 , wherein the liquid components comprise one or more of: a water reducer, an air-entraining agent, and a set retarder.