STRENGTH ANALYSIS WITH RESPECT TO MODE OF PREPARATION OF CONCRETE AND SANDCRETE BLOCKS

Cases of structural failures have been recorded around the world in cases such as the Ranza Plaza in Bangladesh, Sampoong Departmental Store in South Korea, Royal Plaza Hotel in Thailand, the Highland Towers in Malaysia and the Versailles Wedding Hall in Jerusalem (Anon., 2010) [6]. Similarly, some structural failures recorded in Ghana include the Achimota Melcom building and the NiiBoi Town hotel (Ansah, 2014) [15]. Most of the cases recorded in Ghana revealed shoddy works by construction companies which included, not subjecting blocks to appropriate tests, material and machine error. This paper assesses various proportions of cement and aggregates used and their contribution to strength of concrete and sandcrete blocks. Cracks can be broadly classified as either active or dormant. Active cracks show change in direction, width or depth over a measured period of time while dormant cracks remain unchanged. If left unrepaired, both active and dormant cracks provide channels for moisture penetration, which can lead to future defect (Almherigh, 2014,Anon., 2016) [3, 14].Although concrete may be load-bearing, the presence of cracks could facilitate the ingress of aggressive agents leading to deterioration and failure (Kristiawan, 2006) [21].Design of the mixture must consider the environment of production or use as inexposure to sea water, passage of traffic, foot bridge or extreme proximity to high temperatures (Anon., 2013) [10].