Comparison Of Compressive Strength Between Fine Aggregate And Local Aggregate

ABSTRACT

The use of two types of course aggregates for different works is examined in this study. Typical strength concrete is being made from various aggregates and their impact on various characteristics to the subsequent concrete. Compressive strength is the most vital property of a concrete. In this paper, two forms of coarse aggregates, fine aggregate (granite) and local aggregate utilized. Initial laboratory examination was carried out to establish the appropriateness of utilizing the aggregates for construction purpose. Particle size distribution (sieve analysis) and slump test were investigated. Mix ratio (1:2:4) was used for this work and mix structures were analyzed by absolute weight technique. A total of 32 cubes (150×150×150mm) were cast to permit the compressive strength to be observed at 7, 14, 21 and 28 days. Higher compressive strength at all period was observed with concrete produced from fine aggregate. Compressive strength patterns were suggested as a result of age at curing.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

• BACKGROUND OF THE PROJECT
• AIM OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• PURPOSE OF THE PROJECT
• PROJECT ORGANIZATION

CHAPTER TWO

LITERATURE REVIEW

• AN OVERVIEW OF AGGREGATE
• AGGREGATE ORIGIN AND GEOLOGY
• TYPES OF AGGREGATES
• THE EFFECT OF AGGREGATE PROPERTIES ON CONCRETE

CHAPTER THREE

3.0     MATERIALS AND METHODS

CHAPTER FOUR

4.0      RESULTS AND DISCUSSION

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION

CHAPTER ONE

1.0                                          INTRODUCTION

1.1                            BACKGROUND OF THE STUDY

Concrete is a very important material in the Nigerian construction industry as over 90% of her storey buildings are made from reinforced concrete (Joshua et al., 2013a). In the same vein, Tiwari, et al. (2016) posit that the annual global concrete consumption is estimated to be about 25 billion tonnes. Recent studies by Olajumoke and Lasisi (2014), Ode and Eluozo (2016), and Sulymon, et al. (2017) have demonstrated that the quality of concrete is affected by the choice of coarse aggregate used in its production. Aggregates account for about 60- 75% of the total volume of concrete mix and 70-85% of weight with coarse aggregate contributing to about 45-55% of the total mass (Bamigboye, et al. 2016a, Aginam, Chidolue and Nwakire, 2013). The significance of aggregate as noted by Alexander and Mindess (2010) include not only being a filler material but has important physiognomies in improving the workability of a fresh concrete. Additionally, the properties of hardened concrete such as volume stability, unit weight resistance to destructive environment, strength, thermal properties are major roles of coarse aggregate in Portland cement concrete production. Thus, the choice of aggregate in concrete production can significantly affect the performance of a concrete.

The high cost of building materials has led to a clamor for alternative materials. The challenge for the use of locally source materials for the construction of building is as a result of such clamour and has been linked to strategies to reduce the cost of buildings and construction. This could be achieved by the use of materials that are indigenous to the construction location, hence reducing haulage and importation cost of sourcing construction materials from other places. In Joshua et al. (2011), Joshua et al. (2013b) and Joshua et al. (2014), incorporating laterite into sandcrete block production reduced the unit cost of the blocks by about eleven percent (11%). Similarly, incorporating local industrial wastes such as Palm Kernel Nut Waste Ash (PKNWA) as a pozzolan, blended with various classes of cement also produced greener, more durable and more affordable cements (Olusola, et. al., 2012; Joshua, et. al. 2017a; and Joshua, et. al. 2017b). Other studies have also used construction management tools to optimize housing procurement cost (Amusan et al., 2013; Amusan, et al. (2017) and Ogunde, et al. 2017). Indigenous materials and principles were also incorporated to achieve green building (Nduka and Sotunbo, 2014; Nduka and Ogunsanmi, 2015; and Nduka and Ogunsanmi, 2016).

In an effort to meet up with the increasing housing deficits, the demand for locally  sourced aggregate (gravel) in concrete production continue to rise. The reasons for the choice of gravel as an alternative to quarry-crushed stones are not far-fetched. Sulymon, et al. (2017) attributed this reason to increase in population, personal earnings, state infrastructural needs and state wide economic growth. Furthermore, the high cost of fine aggregate due to high energy consumption during rock blasting and local transportation is also a concern in the built environment. Tiwari, et al. (2016) assert that “about half of coarse aggregates used in Portland cement concrete in North America are gravels”. Although studies of Ede, et al. (2016) have shown reservation on the use of gravel for concrete production. This concern is due to local aggregate composition of varied chemicals and strength inadequacy, local variation in size distribution, degree of sorting and composition of deleterious materials when compared to fine aggregate. However, the adoption of locally sourced aggregate (gravel) is not prohibitive once their engineering properties are known.

Local aggregates (like gravel) are formed from natural weathering of parent rocks and eventual transportation of the weathered products by wind and erosion. They are obtained by dredging from pit, lake, river and seabed. Their classification is usually as those having an upper (D) sieve size larger than 4mm wherein the combination of d and D indicates whether the gravel is single sized or graded (BS EN 12620). Bigger sizes can be described as pebbles, cobbles or boulders. Gravels (locally sourced) are commonly round in shape which give rise to lower quantity of cement paste to about 4-5 % in concrete production (Brady, Clauser and Vaccnri, 2002).

Empirical studies have been conducted on mechanical properties of concrete made from locally sourced gravel in Nigeria. Aginam, et al. (2013) investigate various coarse aggregate impacts on the compressive strength of concrete in South-East Nigeria. The experimental study revealed that local aggregate produced the least compressive strength of 16.9kN/m² compared to 20.0kN/m² of local aggregate. They deduced that there is a positive relationship between concrete strength and internal structure, surface nature and shape of aggregates. In the same vein, Olajumoke and Lasisi (2014) evaluated the strength of concrete made with dug-up gravel available in Ile-Ife area of South-west Nigeria. The study showed that there was significant increase in compressive strength when the gravel used was washed. In determining the compressive strength of fine and local aggregate at different mix ratio, Ode and Eluozo (2016), found out that impurities on gravel impacts on the compressive strength of concrete prepared with unwashed gravel. They inferred that there is a positive relationship between strength, stiffness and fracture energy of concrete and type of coarse aggregates.

Bamibgoye, et al. (2016b) undertook particle size distribution analysis, slump test and compressive strength on hardened concrete in exploiting economics of gravel as a substitute to granite in concrete production. They found out that higher composition of fine aggregate significantly improves concretes’ consistency property while greater proportions of granite do significantly enhance compressive strength. Also, Sulymon, et al. (2017) reported that sources of gravel greatly influence compressive, flexural and split-tensile strength of concrete. Hence, this paper will draw on the recent studies in investigating the strength properties of concrete produced from locally sourced unwashed gravel with maximum aggregate sizes of 5mm from Ota, Ogun State, Nigeria.

The study area, Ota, Ogun state, Nigeria is well known for its industrial center and population over flow from Lagos State and currently the most industrialized state in Nigeria (Edike and Ayeni 2017). The increasing population growth rate has influenced the rapid construction of buildings in all nooks and crannies of the state. It is a common practice within Ota environs to use unwashed gravel for construction purposes. Hence, it becomes imperative to investigate the integrity of this aggregate to ascertain its performance in the use of structural members. This paper aims at determining the effects of unwashed gravel on the compressive strength of concrete with a view to furthering the knowledge of aggregate choices for construction works. This study also seeks to encourage the use of this indigenous locally sourced gravel in construction works, to maintain the reduced concreting cost within the study area. This is intended to be achieved by researching into ways the gravel could be treated before use to eliminate the possible deleterious effects on concrete durability.

1.2                                       AIM OF THE STUDY

The main aim of this work is to carry out a comparative study on the fine aggregate (granite or washed concrete) and locally sources aggregate in term of their compressive strength. The objectives are:

1. To determine the correct aggregate to be used in construction work
2. To determine the effects of fine and locally sourced aggregate on the compressive strength of concrete

• To carry out empirical studies on mechanical properties of concrete made from locally sourced gravel in Nigeria

1.3                             SIGNIFICANCE OF THE STUDY

Determining the effects of fine aggregate and locally sourced aggregate on the compressive strength of concrete will help in furthering the knowledge engineers on aggregate choices for construction works.

1.4                                  PURPOSE OF THE STUDY

The main purpose of this study is to be able to make right choice of building material to be used in building construction.

1.5                                 PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.

CHAPTER FIVE

5.1                                           CONCLUSIONS

The main goal of the current study was to study the effects of local aggregate on concrete property and to compare with fine aggregate with a view to restricting its use to applications that can accommodate its ill properties. The following conclusions were drawn from this study:

• Fine aggregate will require more water to be workable hence could be adduced for reduced compressive strength. However, local is not suitable for construction of structural members in multi-storey
• From the sieve analysis, decomposable materials and other dirts were observed in the fine aggregate that could potentially affect the strength development of the concrete. Also, very fine particles were also observed which could be silt, clay and
• It was observed that concrete prepared with fine aggregate achieved better compressive strength than those made with local aggregate. This study validates the previous studies ((Aginam, et al., 2013; Olajumoke and Lasisi, 2014 and Ode and Oluozo, 2016).
• The findings in the current study may be of practical importance to stakeholders in the construction industry (i.e. contractors, clients, government, policy makers, and so on) that could adequately adjust their implementation and development plans based on the results of the

5.2                                          RECOMMENDATIONS

• Notwithstanding the limitations of differences in compressive strength due to variation in compaction, the study suggests that gravel obtained with impurities should be sieved and washed before use in concrete
• The utilization of fine aggregate is strongly advised in higher strength concrete applications like in high rise buildings where strength compromise cannot be accommodated. Even if gravel is to be used in high higher strength applications, it should be sieved and the coarse content washed before
• However, local aggregate can be used for concrete production in blinding and mass concrete works. Evaluation of the aggregates for strength capabilities is crucial to the sustainable growth of the construction industry and the economy in
• Further studies should investigate on how to improve the utilization of gravel for higher strength