ABSTRACT
A study of the properties of sandcrete hollow block 1s important since they are widely used in the construction industry. An understanding of these properties is essential if blocks are to be used effectively., These properties have an important bearing on the appropriate application of the products and on the precautions to be taken to ensure their satisfactory behavior in service. In this thesis, attempt have been made to present the current practices involved in the manufacture of sandcrete hollow blocks in Kaduna State. Various visits to various block industries were made and samples were taken from five industries that are fairly scattered in their location within the state. Tests including dry development strength, wet compressive strength, wet development strength, drying shrinkage, moisture movement, density etc. were performed on the samples. The work further points out the relationship between the wet development strengths at various soaking ages and the dry development strength at 28 days. From the results, one observe that the 20 -- days development strength of industries A,B,C.D and E are 0.08N/mm2, 1.02N/mm2, 0.9N/mm2, 0.77N/mm2 and 0.91N/mm2 respectively. The block samples attained fairly steady strength from the 7th day of curing up till the 28th day. Also the block samples attained a critical condition within 24 hours of immersion prior to testing for wet development strength. The average wet compressive strength of industries A,B,C,D and E are 0.47N/mm2, 0,584N/mm2, 0.550N/mm2, 0.501N/mm2 and 0.547N/mm2 respectively. While the average density of the block samples is 994Kg/mm3. These values however do not satisfy the relevant standards.