Abstract: Concrete is a common material used in the Nigerian building industry. It is obtained by mixing cementitious materials, water, fine and coarse aggregates and sometimes admixtures in required proportions. Admixtures are added to concrete to modify its properties so as to make it more suitable for any situation. In recent times, building collapse in Nigeria has been a source of concern particularly to those associated with the building industry. This has necessitated the need to check the effect admixtures have on some properties of concrete. This study investigated the effect of calcium chloride (CaCl2) as an admixture on the compressive strength of concrete produced from Dangote, Elephant and Burham brands of cement available in Nigeria. The impact of calcium chloride admixture on the compressive strength of concrete made from these brands of cement was compared with the compressive strength of concrete without calcium chloride. Sieve analysis, natural moisture content and specific gravity tests were carried out on the aggregates used in the production of the concrete and the results were recorded. Slump tests were carried out on the fresh concrete containing CaCl2 and without CaCl2 and the results were also recorded. Cubes produced from the concrete were cured for 7, 14, 21 and 28 days respectively. The mean densities of the concrete cubes made from the three brands of cement with and without admixture were computed. The corresponding mean compressive strength for the concrete cubes was also computed. The results showed that concrete with calcium chloride have higher compressive strength compared with those without calcium chloride.Abstract: Concrete is a common material used in the Nigerian building industry. It is obtained by mixing cementitious materials, water, fine and coarse aggregates and sometimes admixtures in required proportions. Admixtures are added to concrete to modify its properties so as to make it more suitable for any situation. In recent times, building collapse in N...Show More
Abstract: This research investigated and compared the strength of manual with machine compacted sandcrete hollow blocks using Dangote and Elephant (Ordinary Portland) cement brands in Nigeria. Thirty two (32) samples were moulded from the two brands of cement i.e. sixteen (16) from each cement brand for both manual and machine compaction methods and were cured for 7, 14, 21, and 28days respectively. The result revealed that the 28th day average compressive strength of the block produced manually with the Dangote and Elephant brands of cement were 2.83N/mm2 and 2.89N/mm2 respectively, while the 28th day average compressive strength of machine compacted blocks from Dangote and Elephants brands of cement were 2.96N/mm2 and 3.03N/mm2 respectively. This result revealed that machine compacted blocks have a higher compressive strength than the manually compacted blocks. The result obtained for all the samples of the sandcrete blocks were within the Nigeria Industrial standard (NIS 87:2000) specification.Abstract: This research investigated and compared the strength of manual with machine compacted sandcrete hollow blocks using Dangote and Elephant (Ordinary Portland) cement brands in Nigeria. Thirty two (32) samples were moulded from the two brands of cement i.e. sixteen (16) from each cement brand for both manual and machine compaction methods and were cur...Show More
