INVESTIGATION OF THE COMPRESSIVE STRENGTH OF COMMERCIALLY PRODUCED SANDCRETE BLOCK

CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF STUDY
The frequent failure of buildings in Nigeria is a concern to all stakeholders. In the past incessant building failures have been reported resulting in the loss of lives and properties in Nigeria, Fakere, et al (2012); Oyekan & M., (2008). The global concerns for sudden collapses of buildings across the world, and in Nigeria in particular demand that materials used for construction of buildings meet minimum requirement Ukpata,( 2006). In some cases, even though the building has not totally collapsed, the aesthetics value is lost to cracks and other defects. Part of this problem is due to the poor quality of sandcrete blocks used as walling units. Sandcrete block is a common building material used in Nigeria and sub-Sahara Africa, and accounts for more than 60% of materials in most buildings.
Sandcrete blocks appear to be the most commonly utilized walling unit in the South-South region of Nigeria. Perhaps due to the heavy rains experienced in this part of the country, earth block technology is not popular around the Niger Delta region of the country. This has placed a high demand on inert materials such as sandcrete blocks for housing development. According to Abdullahi (2005), over 90% of physical infrastructures in Nigeria are being constructed using sandcrete blocks. However, operators of commercial blocks tend to take advantage of this high demand to deliver low quality products. Sometimes due to demand pressures, the blocks are not adequately cured among other practices such as poor compaction and inadequate cement content thus lacking the basic engineering properties.

The Nigerians governments in 1985 setup a committee to review the allowed minimum permissible compressive strength of sandcrete blocks in the country. The committee took into account the weights that can be easily handled by the brick layers. The committee primary aim is to ensure that sandcrete blocks is produced to meet with the required engineering standard.
Thus the focus of the present study is to investigate the quality of commercial produce sandcrete block for construction and compare it with the recommended standard.

1.2 STATEMENT OF PROBLEM
The industry lack of commitment to (NIS 87: 2000) standard requirement is a common problem affecting the construction industry in Nigeria. The weakness of regulatory Authority in Nigeria openes ways for personal gains and business opportunity exploitation. Andam (2004) showed that commercially produced sandcrete blocks exhibit compressive strengths below that which is recommended by standard for construction. He went further to indicate that maximum compressive strength of commercially produced sandcrete blocks was within the range of 0.87N/mm2 as against minimum recommended standards of 1.75N/mm2 Ezeji (1997) showed that the relative proportions and number of components considerably affect the mixing rate with cement Neville (200) identified that the compressive strength of a sandcrete material increases cements contents with limit rate. This means the type of sand material used, such as fineness, density, relative density and sharpness seems to have direct influence on easy mixing, compaction appear to have direct impact on the strength. Increase in strength with age and curing temperature, also seems to contribute to the stabilization of sandcrete blocks. All the information available sandcrete block industries has be ignored for their own benefit.

1.3 AIM AND OBJECTIVES
This study is aimed at investigating the compressive strength of commercial produced sandcrete block in Eket, Akwa Ibom State and also verify if it meets the recommended standard as stated in NIS 87: 2000. To achieve this aim, sandcrete blocks samples from random selected block producing firms in Eket will be collected to the laboratory for curing and testing, and the obtain structural characteristics will be compared recommended standard.

1.4 SIGNIFICANCE OF STUDY
The eventual gains in this research cannot be overemphasized. There are immense benefits to those who research in this area. Producers of sandcrete blocks will benefit immensely from the results of this research work through the following ways;
Their fears on quality of blocks produced must have been cleared.
They can be sure they achieve the target strength, yet not sacrificing their profit.
Their reputation shall increase and closure by Government for not measuring to standards required or specification must have been a thing of the past.
Contractors who use these materials for construction would be sure of using standard hollow blocks produced as such.
The structures built with such blocks shall stand the test of time and the usual cracks and deterioration in construction industries must be reduced drastically.
The eventual users of these buildings must be set free from unnecessary maintenance and huge expenses therein, hence very happy with the buildings they live in or use for office, etc.

1.5 SCOPE AND LIMITATIONS
This project work is limited to the investigation of strength properties on commercially produced sandcrete blocks.