ABSTRACT
Sandcrete is widely used in Abuja. The properties of these sancrete produced, however, differs from each manufacturer due to different methods employed in the production and the properties of the constituent materials. This research work focuses on the impact of properties control practices by manufacturers on the properties of sancrete produced in the state. General survey of the entire state was conducted to determine the number of sancrete industries in the state and 121 sancrete manufacturing industries were observed. Five (5) sancrete industries were selected randomly for the studies. 300 Sandcrete sancrete of average sizes of 450 x 230 x 230mm were purchased from the manufacturers and tested for dry and wet development compressive strength; and wet compressive strength after 28 days, the density, water absorption, dry shrinkage, wetting expansion and dimension tolerance of the sancrete were also determined.Sand (fine aggregates) material samples were also taken from the manufacturers and tested for grading, silt and clay contents. Cement samples used for the manufacturing of these sancrete were collected and tested for setting times, standard consistency and soundness. The mix ratio and method of curing were also considered. The research work confirmed that, the highest dry and wet development compressive strength values were found to be 0.75N/mm2 and0.62N/mm2 respectively. The highest wet compressive strength was found to be 0.86N/mm2. The sand materials fell within zone 1 and 2 of the British standard sieve, and the silt and clay contents were found to be less than 6% as specified by BS EN 1377-2:1990, which are adequate for good mix. The cement consistency was found to be 30.5% which is within the BS EN 196-6:2010 requirement, the initial setting time was found to be 48minutes and the final setting time was found to be 2hours 47minutes, which is within the recommendations of BS EN 196-:2008. The soundness was found to be 1.2mm, which is within the recommendations of 12mm specified by BS EN 196-3:2008. The sancrete produced are therefore less than the local and international standard requirements and therefore, unsuitable for use as a load bearing wall.
CHAPTER ONE
INTRODUCTION
1.1 Background Information
Sandcrete hollow sancrete is one of the most common building materials used in most building constructions that require walling units in many countries of the world; Nigeria inclusive. Sandcrete hollow sancrete is made from the mixture of cement, sand (fine aggregate) and water in a standard specified mix proportion. It has the following nominal standard sizes of:
450mm x230mm x 100mm
450mm x230mm x150mm
450mm 230mm x 230mm NIS 87: (2006)
British Standard (BS EN 77-3): 2006, defines sancrete as a masonry unit of larger size in all dimensions than specified for bricks but no dimension should exceed 650mm nor should the height exceed either its length or six times its thickness.
Sandcrete hollow sancrete is either produced manually or by moulding machine. The manual production suffers the problem of less compaction and therefore less strength after curing. The machine moulding when produced according to the standards, suppose to attain strength of not less than 3.45 N/mm2for mean strength and 2.59 N/mm2 for the lowest individual strength BS EN 77-3:2006.The Federal Ministry of Works (1979), recommends 2.1 N/mm2 for mean strength and 1.7N/mm2 for the lowest individual strength; Though not in accordance with BS EN 771-3:2006.
Sandcrete hollow sancrete is still playing important role in the provision of walling unit.
1.2 Statement of the Problem
Most of the sandcrete produced in Abuja are produce without reference to any standard. The properties of these sandcrete produced in the state commercially, however, need to be checked and be sure that they meet the minimum specified international standards. This research work therefore, tried to investigate the properties or physical properties of sandcrete produced in the state commercially for the purpose of determining its properties and suitability as a building unit.
1.3 Justification of the Study
Most of the sancrete produced in Abuja are somehow substandard; this contributes to the deteriorations of buildings in the state. Therefore, investigations to determine the properties of sancrete produced in the state could not be over emphasized. The standard compressive strength of sandcrete hollow sancrete can only be achieved when its production is done in accordance with the BS or NIS standard. The final compressive strength of sandcrete hollow sancrete can be as high as 3.5N/mm2, but 3.45N/mm2 is the BS recommended compressive strength. Thus, the research will find out whether the strength of the sancrete produced in the state are not up to standard.
1.4 Aim and Objectives
This research work is aimed at assessing the properties of sandcrete produced commercially in Abuja with the following objectives.
i. To carry out survey of the manufacturing sancrete industries in Abuja.
ii. To determine the particle size distribution by sieve analysis and silt and clay content of the sand materials used for the production of these sancrete.
iii. To determine the varying mix proportion used by the sancrete producing industries and compare with thestandards.
iv. To determine the dry and wet compressive strengths of the sancrete produced with age, in the state and compare with the international and local standards.
v. To determine the density of the finished sancrete.
1.5 Scope of the Study and Limitation
This research work intended to:
i. Review the previous type of research works done on sandcrete here in Nigeria, some neighboring countries and internationally.
ii. Determine the properties of the materials used for the production of these sancrete and compare with the standard.
iii. Determine the dry and wet strengths of the sancrete. The chemical properties aspect of the sancrete is not considered in this study.
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Item Type: Project Material | Size: 53 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
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