Effect of Cement Grades on some properties of Sandcrete

Abstract

The purpose of this study is to investigate the effects of cement grade on some properties of sandcrete. The cement used for this work was Ordinary Portland cement (Dangote brand) of grade 42.5 and 32.5 meeting the requirement of ASTM C150 type 1 cement. Three types of fine aggregate was also used to produce sandcrete cubes which includes Ovbiogie sharp sand, Okhuahe sharp sand and Iguosa river erosion sand all obtained from Benin city , Edo state, Nigeria. Sieve analyses were carried out on the three fine aggregate samples which fell under zone 3 according to BS 882:1954. Sand/cement ratios of 1:6, 1:8 and 1:10 were used to produce a total of 216 samples of 150mm x 150mm sandcrete cubes. The work studied the compressive strengths of the various sandcrete cubesat curingages of 1, 3, 7 and 28 days respectively.

The results obtained using grade 32.5 cement at 7days with sand/cement ratio 1:6 are 3.48N/mm², 3.30N/mm² and 3.21N/mm² for Ovbiogie sand, Iguosa sand and Okhuahe sand samples respectively. For sand/cement ratio 1:8, the compressive strength of the sandcrete cubes are 3.03N/mm², 2.34N/mm², and 2.43N/mm² for Ovbiogie sand, Iguosa sand and Okhuahe sand samples respectively. These met the Nigerian Industrial Standard (NIS, 1975) for load bearing blocks and non-load bearing blocks. Using grade 42.5 cement, the results also obtained, for 7days with sand/cement ratio 1:6 are 6.52N/mm², 6.03N/mm² and 6.22N/mm² for Ovbiogie sand, Iguosa sand and Okhuahe sand samples respectively. For sand/cement ratio 1:8, the compressive strength of the sandcrete cubes are 5.48N/mm², 3.69N/mm², and 2.89N/mm² for Ovbiogie sand, Iguosa sand and Okhuahe sand samples respectively. These also met the Nigerian Industrial Standard (NIS, 1975) for load bearing blocks and non-load bearing blocks. This study has shown that cement grade does not translate to sandcrete strength.