TY - JOUR AU - G. G. N. N. Amarakoon, AU - Takefumi Koreeda, AU - Satoru Kawasaki, PY - 2015/12/12 Y2 - 2024/03/28 TI - EFFECT ON UNCONFINED COMPRESSIVE STRENGTH OF SAND TEST PIECES CEMENTED WITH CALCIUM PHOSPHATE COMPOUND JF - GEOMATE Journal JA - INTERNATIONAL JOURNAL OF GEOMATE VL - 7 IS - 14 SE - Articles DO - UR - https://geomatejournal.com/geomate/article/view/2981 SP - 1070-1075 AB - <p>Chemical grout is composed of a calcium phosphate compound (CPC) which develops to<br>form calcium carbonate (CC) precipitation throughout the soil and leading to an increase in soil strength. In this<br>paper, initially the condition for CPC precipitation by using different mixtures of calcium and phosphate stock<br>solutions were investigated and analyzed. For that, Toyoura sand test pieces were cemented by CPC solutions<br>and cured up to 28 days and carried out unconfined compressive strength (UCS) test. Moreover, Toyoura<br>sand test pieces were cemented by CPCs with scallop shell (SS) powder and cured and these specimens also<br>analyzed with UCS tests. The UCS of the sand test pieces cemented by CPC with SS powder was larger than that<br>of the test pieces with no added powders. The UCS of Toyoura sand test piece cemented with the CPC-SS<br>powder method increased to a maximum of 156.9 kPa. Moreover, the best CPC-Chem mixture for cementation is<br>CA: DPP with the concentration of Ca/P ratio is 0.5. In addition pH concentration, scanning electron microscope<br>(SEM), and density before and after curing were observed. The results indicate that the density and the pH<br>concentration of the sand test pieces cemented by CPCs with SS powder were larger than that of the sand test<br>pieces with no added powders. SEM images of test pieces cemented with CA: DPP mixture by addition of SS<br>powders not clearly identified a crystal formation among particles of Toyoura sand.<br><br></p> ER -