Effect of addition of phosphate powder on unconfined compressive strength of sand cemented with calcium phosphate compound

Abstract

For the purpose of improving a novel grout composed of a calcium phosphate compound (CPC-Chem), we have conducted an unconfined compressive strength (UCS) test on samples cemented with CPC-Chem and tricalcium phosphate (TCP) powder. The UCS of these test samples was significantly larger than the UCS of the non-additive test samples. The UCS reached the targeted value of over 100 kPa, and after 28 days of curing, reached a maximum of 261.4 kPa. Additionally, the pH of the samples cemented with CPC-Chem and TCP powder was weakly acidic. These results suggest that the novel geotechnical method using a combination of CPC-Chem and TCP powder has the potential to be used as a non-contaminating and recyclable application, as a biogrout that uses microbial activity and for ground improvement because it satisfies the strength requirements for practical use. © 2013 The Japan Institute of Metals and Materials.