-
The Effect Of Admixtures On Properties Of Co`ncrete
[CASE STUDIES OF SUGAR, COW BONE ASH, GROUDNUT SHELL ASH, AND LIME STONE POWDER]
CHAPTER TWO -- [Total Page(s) 6]
Page 3 of 6
-
-
-
While inorganic retardants include; oxide of lead and zinc, phosphates, magnesium salt fluorides, soluble zinc, soluble borates etc.
3. Air-entrainers: These are probably the most important group of admixtures. They improve durability of concrete; in particular, it’s resistance effect of frost and de-icing salts. The entrainment of air in the form of very small and stable bubbles can be achieved by using framing agents based on natural wood resins, animal or vegetable fat and synthetic detergents which promote the formation of air bubbles during mixing or by using gas-producing chemicals such as zinc or Aluminium powder which react with cement to produce gas bubbles. other air entraining agent are neutralized vinsol resins, polyethylene oxide polymers and sulphonated compounds. First method is generally more effective and widely used. The beneficial effect of entrained air are produced in two ways:
i. First, by disrupting the continuity of capillary pores and thus, reducing the permeability of concrete, and
ii. Second, by reducing the internal stresses caused by the expansion of water on freezing.
Air-entrainers also improve the workability and cohesiveness of fresh concrete, ease of placing, tend to reduce bleeding and segregation. However, entrained air result in some reduction in concrete strength since improvements in workability can permit a reduction in water content, the loss in strength can be minimized, the amount of entrained air depend on the type of cement, mix proportions and ambient temperature and it should therefore be used only when adequate supervision is assured.
4. Water reducer or plasticizers: Most retarders are also used for this purpose for example lingo-sulphuric and hydroxylated carboxylic acids. other water reducing agent is calcium or sodium salt of lingo-sulphuric acid and poly carboxylic acid. Their effect is tough due to the increase in dispersion of cement particles causing a reduction in the viscosity of the concrete.
Water reducers or plasticizers are used for the following;
i. Concrete having greater workability be made without the need for more water and so strength losses are not encountered,
ii. By maintaining some workability, but at a lower water content, concrete strengths may be increased without the need for further cement addition,
iii. While maintaining the same water-cement ratio and workability concrete can be made to a given as in the reference concrete at lower cement content.
2.3 SELECTED AGENT
2.3.1. Limestone Powder (LP)
According to International Journal of Innovation Research in Science, Engineering and Technology (Vol 2. Issue 9, September 2013), describes, Limestone Powder (LP) is produced as by – product of limestone crushers – large volumes of this powder are accumulated and it is a big problem. Utilization of this by – product may solve the problems related to disposal, environmental pollution and health hazards.
Limestone powder has been used to produce cement in some countries, it is maintained that up to 35% of limestone.
Powder in concrete, particularly in self – compacting concrete (SCC), has been widespread in Sweden and France where limestone powder is stoned in silos along side.
The cement in ready – mix concrete plants. The addition of fine limestone powder can significantly improve. The workability of SCC and it thus shown to enhance the rate of cement hydration and strength development, as well as to improve the deformability and stability of fresh SCC
Raju Krishan (2003), described limestone as a rock containing at least 50% calcium carbonate but generally not including such rocks that have been re-crystallized and chemically altered by metamorphism. Limestone are typically soluble in cold dilute acids and have a specific of 2.6 they are soft, for calcite the most abundant mineral constituent has a hardness of only 3 and are white to cream-colored unless stained yellow or brown by iron oxides or rendered bluish to black by included organic matter and iron disulfide. Limestone are typically well cemented and without large amount of intra-granular porosity although chalk and calcareous sinter are incoherent and early. Limestone is appreciable soluble in water enriched in organic acid and carbonic acid such as ground water which has passed through soil.
Salami (2002), most limestone are partly or entirely origin. The soft whitish limestone known as coquinas are composed almost entirely of shells fragment and were formed in warm shallow water like that around the patinas today where organism grew abundantly and the waves were able composed of foraminifera. Such as Globigerina. Limestone is a retarder; it is used in the production of sodium carbonate from sodium chloride by the Solvay process. The manufacture of aluminium oxide (alumina) by the Bayer process. Production of synthetic phenol, calcium nitrate, dyestuffs and intermediate and the refining of beef sugar by the carbonation process. It is a food supplement for livestock and poultry and is used in whiting and as reactant in the refining of salt brines and the manufacture of glass. The calcinations of limestone at temperature high enough to dissociate calcium carbonate yield both carbon dioxide and lime for commercial use. The latter is used in the construction industries and in manufacturing chemical including calcium carbide which is produce by fusing lime with coke
CHAPTER TWO -- [Total Page(s) 6]
Page 3 of 6
-
-
ABSRACT - [ Total Page(s): 1 ]ABSTRACT The project titled “The effect of admixtures on properties of concrete: case study of sugar, cow bone ash, groundnut shell ash, and lime stone powder†was carried out with the aim of knowing the effect the of the various types of admixtures used on the properties of concrete, in term of the workability of concrete, durability of concrete and the concrete strength. The material used are cow bone ash, groundnut shell ash, sugar and lime stone powder. The cow bone was sou ... Continue reading---
LIST OF TABLES - [ Total Page(s): 1 ]LIST OF TABLESTable 4.1: Data Analysis for Fine Aggregates (Sand) Table 4.2: Data Analysis for Coarse Aggregate (Granite) Table 4.3: Slump Test Result for GSA Concrete Table 4.4: Slump Test Result for CBA Concrete Table 4.5: Slump Test Result for Sugar Concrete Table 4.6: Slump Test Result for LP Concrete Table 4.7: Summary of Slump Test Result for Various Concrete Admixtures Table 4.8: Compressive Strength Test Result of Normal Concrete Table 4.9: Compressive Strength Test ... Continue reading---
LIST OF PLATES - [ Total Page(s): 1 ]LIST OF PLATESPlate 3.1: Groundnut Shell and Cow Bone Plate 3.2: Burning of Groundnut Shell and Cow Bone Plate 3.3: Cow bone ash, Groundnut shell ash, Limestone powder and Sugar. Plate 3.4: Batching of Concrete Plate 3.5: Type of Slump Plate 36: Cube Production Plate 3.7: Curing of Cubes Plate 3.8: Crushing Machine ... Continue reading---
LIST OF FIGURES - [ Total Page(s): 1 ]LIST OF FIGURESFigure 4.1: The graph of sieve analysis for Fine Aggregate (Sand) Figure 4.2: The graph of sieve analysis for Coarse Aggregate (Granite). Figure 4.3: The graph of slump test result for GSA Concrete Figure 4.4: The graph of slump test result for CBA Concrete Figure 4.5: The graph of slump test result for SUGAR Concrete Figure 4.6: The graph of slump test result for LP Concrete Figure 4.7: The graph for summary of slump test result for various Concrete AdmixturesFigure 4.8: Th ... Continue reading---
TABLE OF CONTENTS - [ Total Page(s): 1 ]TABLE OF CONTENTSTitle Page Declaration Certification Dedication Acknowledgement Abstract Table of Contents List of Tables List of Figures List of Plates CHAPTER ONE 1.0 Introduction 1.1 Statement of the Problem 1.2 Aims and Objectives of the Study 1.3 Justification of the Study 1.4 Scope of the Study CHAPTER TWO 2.0 literature Review 2.1 Concrete ... Continue reading---
CHAPTER ONE - [ Total Page(s): 2 ]CHAPTER ONE1.0. INTRODUCTION The importance of understanding various types of materials used in Civil Engineering is widely recognized. There has been tremendous increase in the latest research and practical achievement to improve on concrete technology. Free exchange for technical know ... Continue reading---
CHAPTER THREE - [ Total Page(s): 8 ]CHAPTER THREE3.0 PROJECT METHODOLOGY For successful accomplishment of the aims and objectives of this project the following methods are applied.i. Market survey for the most commonly used cement was carried out and it was found that elephant and dangote cement are the most commonly used in the locality due to their availability in the market all time.ii. Text books, internet and some experienced practicing engineer are consulted in order to obtain relevant and detailed ... Continue reading---
CHAPTER FOUR - [ Total Page(s): 16 ]D10 = 1.686μmm = 0.169mmD30 = 273.6μmm = 0.274mmD60 = 503.75μmm =0.504mmi. The effective grain size; i.e. D10 = 0.169mmii. Uniformity coefficient, Cu = = = 2.98iii. Coefficient of curvature, Cc = = = = 0.88D10 = 7.6mmD30 = 12.8mm D60 = 15.2mmi. The effective grain size; i.e. D10 = 7.6mm ii. Uniformity coefficient, Cu = = = 2.0iii. Coefficient of curvature, Cc = = = =1.42 ... Continue reading---
CHAPTER FIVE - [ Total Page(s): 1 ]CHAPTER FIVE5.0 CONCLUSION Based on the results of this investigation, the following conclusion is drawn; Admixtures affect properties of concrete like its slump value, density, compressive strength, etc. Admixtures generally decrease the slump value of concrete which in turns decrease the workability of the concrete, since normal concrete(0% concrete) has a slump value of between 55-60mm while concrete with admixture has slump value lesser ... Continue reading---
REFRENCES - [ Total Page(s): 1 ]REFERENCEAkogu Elijah Abalaka (2011): ‘Effects of Sugar on Physical Properties of Ordinary Portland Cement Paste and Concrete.Albadan B.A, M.A Olutoye, M.S Abolarin & M. Zakariya (2005): ‘Partial Replacement of Ordinary Portland Cement (OPC)with Bambara Groundnut Shell Ash (BGSA) in Concrete. Leonard Electronic Journal of Practices and Technologies. Issues 6, pp. 43 – 48, January – June 2005. Aribisala, O.J & Bamisaye, A.J (2006): ‘Via ... Continue reading---
