Significance of Tests and Properties of Concrete - Research Proposal Example

NСRЕTЕ RЕРОRT Name Professor Institution Course Dat Abstract The content of this document describes reports involving the exercise of concrete sample preparation, aggregate grading testing as well as compressive strength testing performed on various samples of concrete. It also highlights the process Hazard Identification Risk Assessment and Control as well as the observation of Occupational Health and Safety measures involved in the exercise of concrete testing. CONTENTS Abstract i CONTENTS i CHAPTER ONE: INTRODUCTION 1 1.1 Background 1 CHAPTER ONE: INTRODUCTION 1.1 Background Design and construction of various structures in the building and construction industry commonly require the use of reinforced concrete. The building and construction works range from simple building structures to more complex ones such as the complex highway bridges. The durability of concrete is a very important consideration for ay structure that uses concrete in its design and construction. Every ingredient in the concrete mixture has to satisfy the requirements that are specified and established in the standards of construction materials as specified by the concerned authorities. The individual components must be used in correct proportions in order to obtain concrete structures that are durable. Low shrinking feature that is experienced in concrete structures is very vital in enhancing the durability characteristics of the structures constructed (Lamond, 2006). It is therefore very important for the aggregate features to obtain significant considerations in order to attain durability in concrete structures. Concrete is a composition of materials that consist of cement materials, aggregates, admixtures, air and water. Concrete in the one main material used in construction and building whose delivery to the construction site can be done in the plastic state. This feature of concrete that makes it unique is desirable in the construction industry due to its ease of mounding into various states. Concrete offers a wide range of colors and surface textures and can be applied in the construction of various structures. The two main components that form the basis of concrete are inert materials as well as the cement paste. The cement paste is normally consisting of water, cement as well as air either in the form of minute or in the form of entrapped natural voids of air. The inert materials are normally consisting of aggregate in fine form which includes materials like sand and other materials. The mixing of cement with water is done; the cement components react leading to the formation of a medium of cementing. In a concrete that is mixed according to the right proportions every coarse aggregate as well as sand particles are completely coated and surrounded by the cement paste. The spaces in the midst of particles are filled with the cement paste. As the paste of the cement hardens and sets, it puts together the aggregates to form a solid mass. Under the conditions that are normal, the concrete becomes older and stronger. The reactions taking place chemically between water and cement causes the aggregate to be bound together by the paste and harden with time. The concrete strength is varied through the mixing up of cement, water, fine and coarse aggregates as well as other additional mixtures. The cement to water ratio is the main determining factor with regard to the concrete compressive strength. For low water cement ratio there is a high compressive strength. A given small amount of water is required for appropriate chemically facilitate action in the concrete hardening (Lamond, 2006). 1.2 Aim The aim of this exercise involving concrete testing through preparing the samples of concrete as well as aggregate grading and compressive strength testing include introducing the group working technique to students as well as introducing students to issues to do with safety and health. The other aim is to allow the students to be conversant with the testing concepts involved in testing and Australian standards. CHAPTER TWO: METHOD 2.1 Methodology Background The methods that were employed in this particular laboratory exercise involving concrete testing required the students participating to work in groups as teams. They engaged in the preparation of the samples of the core concrete as was initially demonstrated to them. In this concrete testing activity the guidelines to do with occupational health and safety management as well as the identification of hazard and the process of assessing and controlling risks were strictly adhered to. In this testing methodology, there was also strict observation of the Australian standards relating testing and the preparation of concrete as well as the methods involved in curing and formation of concrete of concrete through direct tensile and compression specimens. 2.1 Procedure: Concrete sample preparation Each team among the teams of students participating in this concrete testing exercise were expected to employ a give specified mixture to obtain a total of four core samples of concrete the specified mixture ration of water to cement that was specified to every team was done on the basis of weight and the ratios listed as indicated in the table below. Teams of participating students Ratios of water/cement mixture specified 1C, 1D, 2A, 2B, 2C, 2D 0.55 1A, 1B, 4A, 4B, 4C, 4D, 5C, 5D 0.6 3A, 3B, 3C, 3D, 5A, 5B 0.65 Immediately after the preparation of the four core samples of the concrete each team of the participating students was required to rearrange themselves in order to facilitate the removal of the cores away from the molds. This was carried out at around twenty four hours from the time that packing was done which was actually the day that followed. Three of the four core samples of concrete were put into storage that contained water filled temperature controlled curing tank in which case the participating team of students were advised to ensure that they identified their own set of samples and testing apparatus. The other one remaining core out of the initial four core samples of concrete was kept outside in air to dry. Markings that are water proof as well as concrete surfaces with light scratches were used in the identification exercise. 2.1 Procedure: Aggregate grading and Compressive strength testing Compression strength testing was conducted with the use of testing machines for compression in the materials laboratory. The measurement of lengths as well as that of the core diameters was carried out with reference to the laboratory practical guides. The testing of cores was carried out by various teams of participating students at days which were ranging through 7, 14, 21 as well as 28. Each team of the participating students then crushed their cured core that consisted off single air cured and three water cured as their respective prescribed dates. The curing time variation among the various teams of participating student involved was expected to bring about outcomes that are spread. CHAPTER THREE: DISCUSSION 3.1 Hazard Identification Risk Assessment and Control (HIRAC) The concrete testing exercise that involved the preparation of samples of concrete core entailed the observation of Hazard Identification Risk Assessment and Control measure in which case it was identified that the concrete cutting process with the appropriate controls of dust could lead to the generation of elevated levels of dusts containing silica. The inhalation of this kind of dust could bring about serious lung illness which could eventually lead to death. The necessary precautions were therefore taken and noted down in order to assist in development of future exposure control plan for concrete testing exercises. The identification of risks and assessment of hazard involved the establishment of the fact that there were possibilities of presence of high silica percentage in concrete, the cutting or scrubbing of concrete without using the appropriate personal protection equipment in controlling dust would be risky and hazardous. With regard to Occupational Health and Safety measures (OH&S) the occupational limit of exposure for crystalline silica that would be respired was identified to be 0.025 (mg/m3) including quartz 3.2 Data Analysis The analysis of data for the concrete sample preparation, aggregate grading as well as compressive strength testing for concrete was carried out including preparation through mixing, testing as well grading for those that were completed. The final crushing data was determined and tabulated as; w/c Cured Dry Water cured 0.65 28 days 55kN 100kN 160kN 200kN For the compressive strength of concrete testing the determination of the parameters involved was done. The age of the concrete has got a salient point where it is arithmetically related to the strength of the concrete. Older the concrete have larger the compressive strength and the younger the concrete have smaller the compressive strength. The compressive strength for day 7, 14 and 28 concrete has a mathematical relationship with that of day 3. However, it is established that the day 28 old concrete has got a higher compressive strength that the day 3 old concrete. CHAPTER FOUR: CONCLUSION It is clearly demonstrated that the performance of concrete preparation and testing exercise is significant especially with regard to the identification of the compressive strength as well as other features in concrete which my result into the concrete being termed as substandard. Performance of concrete testing is carried out I most case to establish the existing load carrying capacity of a concrete constructed structure. Upon confirmation of reduced carrying capacity of a concrete structure with regard to it compressive strength, the necessary reinforcement measures are taken in consultation with the design specifications. REFERENCE Lamond, J. F. (2006). Significance of tests and properties of concrete and concrete-making materials. West Conshohocken, Pa: ASTM Read More