INVESTIGATING THE COMPRESSIVE STRENGTH OF NORMAL STRENGTH CONCRETE USING POWDERED BURNT BRICK AS PARTIAL REPLACEMENT FOR CEMENT

INVESTIGATING THE COMPRESSIVE STRENGTH OF NORMAL STRENGTH CONCRETE USING POWDERED BURNT BRICK AS PARTIAL REPLACEMENT FOR CEMENT

ABSTRACT

This work determines the production of concrete and partial replacement of powdered burnt brick with cement to produce concrete. The brick was crushed and grinded manually and also sieve through 75 um sieve size in order to be fineness as cement. This project investigates the compressive strength of normal strength concrete using powdered burnt brick as partial replacement for cement. To achieve this aim, two different water cement ratios (0.35 and 0.4 w/c) are introduced in the study. A comparison of this two different water cement ratio, curing days of the concrete at different percentage replacement are carried out. Concrete cubes and cylinders at various replacement level of PBB with OPC were cast for 0.35 and 0.4 water cement ratio to assess the effect of each replacement on their properties. Finding revealed that, 10% PBB replacement has the highest compressive strength and 20% has the lowest for both water cement ratios. The percentage replacement also has the highest compressive strength at 28 days. The compressive strength of concrete at 90 days is high for normal concrete and all PBB replacement level. This implies that the higher the replacement the lower the compressive strength, increase in curing days brings about increase in compressive strength of a concrete and also, the lower the water cement ratio the higher the compressive strength of concrete. The study also ascertained the chemical and physical properties of PBB, which exhibit about 70% binding property of cement. This indicates that, PBB is a good cementations material for binding. It is therefore recommended 0.35 water cement ratio, 10% PBB replacement and day 28 of curing days should all be implemented and encourage because of their high compressive strength characteristics.

CHAPTER ONE

1.1       BACKGROUND OF STUDY

Constructions of houses have always been one of the major problems in Nigeria that requires attention and solution. An inquiry into the likely causes of these problems reveals that construction materials, rural-urban migration and poverty etc. One of the materials used for construction from time immemorial is concrete, it then pose a need to reduce construction cost by submitting expensive and less available material with cheap and readily available materials in concrete for man to build save adequate and low cost structures. (Gidigasu, 1976).

Brick is one of the oldest manufacturing building materials as early as 1400 BC. In Nile deposit at Egypt, dried clay and hand mould brick were found, clay brick is also use for construction of bridges, tunnel, houses, factories and high ways. In ancient cities of Babylonia, fired or burnt brick have been found; some are even about 6000 years old. Bricks are more or less indestructible. Some industries use the process of traditional line or hand making process to produce brick. In 1919, clay work was granted until the middle of 19^th century, manual method have not yet take place. Brick were burnt and mould in kilns until Hoffman introduced a continuous kiln, which enable all process connected with continuous fired carried out.

Clay brick was important raw material for building during ancient time of Mesopotama’s. Modern ancient city of Iraq use mud brick for building around 4000 BC and early Jericho wall around 8000 BC. Clay brick preservation by firing has been recorded and documented from 5000BC. Archeology discovers fired brick which were further developed, such as Euphrates. Different types of brick started developing in most countries and part of Cargo. Most bricks due to their physical and engineering properties throughout building age, which have been used continuously for brick, (Lynch, 1994 and Christine, 2004).

Clay is derived from water borne deposits which produce brick, due to rock particles presence in the brick which make the clay burnt into different brick appearance and color. Concrete is affected by many factors being heterogeneous material, among these aggressive chemicals presence in area where concrete is used. Chemical aggression has been known to produce over whelming or devastating effect of concrete. (Beeby, 1994) to (Maskovic, 1980). Natural source like soil, sea water, carbonates chloride and nitrates. Artificial source like chemical manufacturing industry e.g. fertilizer. The use of chemicals like chloride, sulphates, nitrate and other salts presence in concrete could be responsible for compressive strength of concrete reduction as a result of effect in quality of concrete by (Soroka and shetty, 1980). (Sa’ad, 2005) observed that the degree of loss in ordinary Portland cement (OPC). Concrete compressive strength depends not only the duration of concrete in chemical aggression but it is specifically on the type of acid and its concentration. According to (Neville, 1996 and Lea 1970) they showed that the extend of chemical aggression attack depend on its concentration and its concrete permeability in which water can pass through its. Leaching of ca (OH)₂ extensively will increase porosity so that concrete will become weaker and prone to chemical attack (Ogwu, 2001)) of all magnesium sulphate causes damage to concrete. Whitish appearance characteristic is the indication of sulphate attack (Shetty, 2005, Lea, 1970 and Neville, 1996) staed that calcium aluminum (C₃A) in porous concrete are more prone to chemical aggression attack. Therefore sulphate from concrete attack can be reduced by the use of cement or through the use of pozzolanic Portland cement.

Pozzolans is defined as siliceous materials which itself posses no or little cement properties but in finely divided form, contains moisture and chemically react with Ca(OH)₂ at ordinary temperature to form compound that contain cement properties. Pozzolanic material can also be the material that posses reactive alumina and/or silica, when combined with lime, will react again to form new compound (i.e. calcium aluminum hydrate and calcium silicate hydrate) that have the ability to modify with lime mortar properties. The addition of pozzolan enhances the lime mortar properties by setting time speed, durability, hydraulic setting time which allows increase in strength and property of mortar to cure under water without the action of carbon dioxide. Essentially, the addition of a pozzolan to pure lime is a way of artificially creating material to hydraulic lime. Hydraulic lime is a material that possesses naturally the ability to quickly set in the presence of high moisture because of its reactive silicates contained in the clay mineralogy of the limestone from which it is derived. They are incorporated as active substitution and addition to concrete and OPC due to their reaction with lime. This is originated during Portland cement hydration. (Zelie, 2000). The result of this reaction is the formation of cementitious compound (tricalcium silicate C₃S). This compound modifies some cement properties and results to concrete. According to (shetty, 2005), pozzolana are classified into Natural and Artificial pozzolana where by this classification depends on the nature and sources of pozzolana. Natural pozzolana includes clay, shell, calcite, opaline chart, volcanic ash tuffs and pumice. While artificial pozzolana includes rice husk ash, powdered burnt brick, silica fume fly ash, blast furnace slag and surki. According to (Dahiru and Zubairu, 2008) concrete properties made with rice husk ash (RHA) as partial replacement of OPC in concrete production and they observed that there is increase in strength of concrete at 10% replacement level of OPC for RHA. (Sa’ad, 2005), carried out experiment of OPC with 10% PBB to produce concrete and appreciable compressive strength was obtained. (Garba and Tahir, 2008), carried out experiment on sulphate resistance of cement mortar pozzolanic as further or improved experiment of (Sa’ad, 2005). Therefore this research experiment examined that the effect of PBB in chemical solution of 5% NaSO₄, 10% MgSO4 and 5% H₂SO of compressive strength for the immersion period of 56 days.

1.2       RESEARCH PROBLEM

Dumping of brick powder and other waste brick particles not only cover land but also create problem in the environment. The problem could be less by using waste material to blend with cement concrete.

The reason for using powdered burnt brick includes the beneficial modification of fresh and hardened concrete element of certain properties and also economical gain. The finest of powder burnt brick has great potential for use to blend with sand and cement based repair mortar.

There are obstacles to the successful implementation of this technology in the field. While it is firmly established that powdered burnt brick has the ability to have a pozzolanic reaction with lime and increased in strength. Powdered burnt brick has ability to react with cement depend on a number of variables which will be discuss at length in this study.

The research undertaken in the area of utilization of both Industrial and Agricultural wastes as partial replacement of OPC in concrete production due to economic depression globally, high cost of concrete materials and need to utilize our locally available materials that has been disfiguring our societies as waste material have necessitate the research work into utilization of PBB as partial replacement of OPC in concrete production for the purpose of building. (Dahiru and Zubairu, 2008); (Elinwa and Mahmood, 2002) and (Sa’ad, Garba and Okoli, 2007).

There is need for a simple methods of determining a given brick suitability that can be performed in the field with relative ease, while yielding reasonably accurate and reliable results. Criteria for the ideal field test would include the ability to be performed with limited equipment, limited technical proficiency requirement, and would yield result in a relatively short amount of time. This is particularly important for project or locales that may not possess the resources or technology that is required to make a thorough study to inform the use of the material.

1.3 RESEARCH GOAL

The purpose of this research is to identify an optimal methodology for determining whether a given powdered burnt brick will increase strength when combined with cement. This property will be referred to as strength characteristic property of concrete. The research a review of the   physical properties and mineralogy contents of the material, the nature of the reaction of material in concrete, and a review of existing method for determining the strength of the material. A testing program performed at the laboratory and executed to evaluate different methods for testing brick powder to determine the strength.

As such it is suitable to come up with a suitable material that will be partially replaced with cement to increase the strength characteristic of concrete.

1.4 AIM AND OBJECTIVES

The aim of this research is to determine the effect of compressive strength of concrete with partial replacement of cement with brick powder. The objectives are:

1.     To determine physical and chemical properties of the pozzolanic material PBB.

2.     To determine the compressive strength of water cement ratio

3.     To compare the compressive strength of normal concrete (100% OPC) and partially replaced concrete with PBB.

4.     To determine the compressive strength of each percentage of PBB replacement.

5.     To determine the compressive strength of each curing days of concrete.

1.5       JUSTIFICATION OF STUDY

The study will be beneficial to all member of the construction crew in terms of resolving the problem that arises. It will provide a suitable method of resolving this problem at the best way in a short period of time.

1.6       SCOPE AND LIMITATION

The research is centered to identify those methods used in resolving the problem to determine the strength to the concrete and provide workability. The study is limited to investigate the use of brick powder for partial replacement of cement in concrete, which can be used as construction material in area where brick powder is in abundance. This research also involves the use of the following:

. Concrete cubes size mould.

150mm height and 150mm diameter of concrete cylinder.

The cubes and cylinders will be cured at 7, 14, 21 and 28 days curing period.

The partial replacements of PBB/OPC are 0%, 10%, 15% and 20%.

 1.7       RESEARCH METHODOLOGY

Various materials used for the experimental study were cement, sand, aggregate and Powdered Burnt Brick. Powdered Burnt Brick was collected from a brick manufacturing industry along Paiko road.

Physical properties of brick powder in raw state such as, sieve analysis, compressive strength test, moisture content, and specific gravity and bulk density, workability test and strength test will be determined. In order to prepare the powdered burnt brick (PBB) to be used as partial replacement of cement (OPC), it was processed by grinding/pounding and also sieving the material, using sieve 75 micron in order to make it fine. The grinded brick, referred to as Powdered Burnt Brick (PBB), retaining about 10 percent in 75 micron sieve size which was used in the laboratory. This figure was adopted in order to make the fineness of powdered burnt brick close to that of cement. Ordinary Portland cement and sand passing (5.00 mm) sieve and irregular coarse aggregates passing sieve 20 mm were used in this study. Physical properties of materials used in this study are presented.

The laboratory tests that will be undertaken include:

• Sieve analysis of coarse aggregate, fine aggregate, cement and powdered burnt brick.
• Bulk density and specific gravity of the aggregates.
• Workability test which is the slump test, which ascertained workability.
• Moisture content test of fine and coarse aggregate.
• Setting time and soundness test of OPC cement and compressive strength test.