ABSTRACT
The quality of any building materials or structural unit cannot be over - emphasized as this is vital to the actual performance and durability of structures. This project is a study of the physical properties of sandcrete hollow blocks produced in Kogi State. Site survey covering the entire state was first carried out. About seventy block industries all scattered within the state were visited. During the visit, many factors such as mix ratio, manner of mixing and curing, the condition survey of the current block industries were examined. Quality tests were carried out in the concrete laboratory of Dantata and Sawoe - a civil Engineering and building construction firm based in Abuja. The various tests carried out on the block samples are: the wet development strength, dry development strength, wet and wetting expansion. These tests were done in accordance with the British standard 2028 (precast concrete blocks 1364: 1968 /2/ and the Nigerian Industrial standard. Result from the tests conducted show that, the quality of sandcrete blocks produced in Kogi state do not meet the standard specification of the British standard 2028, 1364 (1968) /2/ and the Nigerian Industrial standard: II: 1974/3/. For example, the maximum 28 - day dry development strength is 1.40N/mm2 while the N.I.S II /3/ specifies 3.45N/mm2. The wet development strength shows low strength at 24 hours of immersion in water then increases gradually to a steady strength in subsequent days. The blocks take about a week to mature for use as evidenced in the dry development strength. Condition survey showed that, there were about seventy block industries scattered all over the state and their methods of curing were not the best.