PERFORMANCE ASSESSMENT OF HIGH STRENGTH LATERIZED CONCRETE

PERFORMANCE ASSESSMENT OF HIGH STRENGTH LATERIZED CONCRETE

CHAPTER ONE

1.0       INTRODUCTION

1.0.1    Background of Study

Laterite is formed by the weathering of rocks under humid tropical conditions and is mainly made of Iron and Aluminium hydroxides (Philip, 1993). Laterite is widely found all over Nigeria and equally in all tropical regions of the world. When fine aggregate is partially or wholly substituted with Laterite in its natural form, it is known as laterized concrete. According to Adepegba. (1975), “It could also be concrete in which Laterite fines are used partially replace the conventional sand”.

Research has shown that Laterite could be used to effectively replace sand up to 50% in structural concrete. ( Kolapo et al, 2012). Ikponmwosa et al 2010; Osadebe et al, 2007. Stated that, “In Nigeria, it is one of the underutilized building materials due to its uncertainty of its strength and other properties”. According to Lasisi and Osunade, 1984. In their study on the effect of grain size on the strength of Laterite cubes found that the finer the grain sizes, the higher the compressive strength. The Compressive strengths in the range of 10MPa to 40MPa has been reported in literatures for laterized concrete prepared from nominal structural concrete mixes (Olusola et al., 2002; Osunade, 2002; Salau, 2003; Olusola, 2005; Udoeyo et al., 2010a and 2010b; Olawuyi et al., 2012). A main consideration in the use of any type of concrete is its quality which is largely determined by its constituent materials. The measures of qualities include satisfactory performance in compressive strength and environmental durability requirements.

It was reported by Udoeyo et al, (2006).  That concrete with 40% replacement of sand with laterite could attain design strength of 20N/mm². When investigating on some characteristics of concrete containing laterite as partial replacement of fine aggregate. According to Ikponmwosa and Falade 2006. In their study on comparative study of strength properties of unreinforced and fibre reinforced normal and laterized concrete, reported that strength increases with age of test specimens, also laterite replacing sand in concrete up to 45% produce the highest compressive strength. Musa Alhassan (2008).carried out an experimental investigation on permeability of lateritic soil treated with lime and rice husk ash, test result showed that the permeability of the cured specimens increased with the curing age at each of the curing ages. The permeability decreases to corresponding minimum at 6% RHA content at specified lime content and an increase in RHA shows a minimal rise in the coefficient of permeability.These studies focus attention on assessing the performance of high strength laterized concrete.

 1.1 Statement of problem

The continuous usage of the traditional fine aggregate in construction for affordable housing leads to its depletion, Hence there is a need to seek alternatives or develop new materials to solve the problem of housing once and for all. This can be further achieved by assessing the performance of high strength laterized concrete. Basically, the use of latcon as building material involves the modification of lateritic soils in its raw form. Laterite has been used in building construction for thousands of years and presently used for shelter for approximately 30 % of the world population (confirman et al, 1990). The use of laterite to wholly or partially replace sand component of concrete, is becoming widespread among the low-income earners for building construction. As reported by Lasis and Osunade, (1984).

1.2 Justification

Laterite soil is elastic in nature and research has shown that it could be used to effectively replace sand up to 50% in structural concrete, by Kolapo O. Olusola (2012). Laterite is found in all   tropical regions of the world. It is found extensively in Nigeria and it is one of the underutilized building materials due to the uncertainty of its strength and other properties. Furthermore, the use of high strength concrete facilitates its application in high-rise building and other structures where strength and size plays a significant role. This is because, constraint in space, these structures rely on their strength and size. This quality is already found in laterized high strength concrete.

1.3 Aim and Objectives

1.3.1Aims

This research is aimed at assessing the performance of high strength laterized concrete, with a view for the usage in hydraulic structures.

1.3.2 Objectives

The objectives include:

1. To cast normal and laterized concrete cube, cured and test for the compressive strength
2. To cast normal and laterized concrete cube of grade 20Nmm² cured and test for permeability
3. To cast normal and laterized concrete cube of grade 40Nmm² test for permeability
4. To compare results obtained from step (ii), (iii)

1.4 Methodology

The materials used were laterite, coarse aggregate, cement (ordinary Portland cement) and fine   aggregate to be obtained from a nearby building material dealer in Minna, Niger state. And making use of 1:2:4 as mix design, using 75 % of sand and 25% of laterite to replace sand.

The methodology to be adopted for this research work was to carry out laboratory test on concrete cubes with size (100×100×100) mm containing the constituent materials. Laterite in 25% and cured for 28 days respectively then crushed to obtain their compressive strength and permeability respectively.

The following tests were carried out in the Building Department laboratory, FUT Minna. Namely, Sieve analysis, Moisture content, Specific gravity, Bulk density, Liquid limit, Plastic limit, Plastic index, and Compaction test, Determination of compressive strength of laterized concrete and Determination of permeability of laterized concrete.

1.5 Scope of the study

This research is based on performance assessment of high strength laterized concrete. The    compressive strength and durability properties in term of permeability for both normal and laterized concrete will be determined.

1.6 Limitations

This research is limited to the percentage porosity of the test specimens which will be used as a means of assessing permeability, in high strength laterized concrete.

 CHAPTER TWO

2.0       LITERATURE REVIEW

2.1       Concrete

Concrete has been the most widely construction material used in construction industries, Concrete is an artificial construction material which is made of mixing of cement, fine aggregates, coarse aggregate and water in the proper proportions. Each of these components contribute to the strength their concrete possesses (Gambhir, 2004). Concrete was defined by Neville, (1995).  As a construction material composed of cement and  other cementitious materials, aggregates,  water and other chemical admixtures which eventually hardens up into a stone like material. The aggregates give strength while Water and cement are the ingredients that react chemically.