Highway Materials, Soils, and Concretes - Research Proposal Example

SOILS AND MATERIALS Name Institution Instructor Date Introduction The need to make classifications of timber on the basis of the strength test on small and clear specimens has always been in place and carried out as a normal exercise. This is the case as a result if the existence of a wide variety of species, variation in materials, continued changes in the supply conditions, several factors that affect the outcomes as well as the ease with which the variables are compared. In the course of preparing for these testing methods with regard to the small clear specimens of timber, important considerations are accorded to the probability of involving various improvements that are desirable with regard to experience and the desirability involved in the adoption of test techniques on the timber specimens that would bring about outcomes that are comparable to the already existing specifications (Hugues, Teiger and Weber, 2008). These techniques of timber testing techniques form the basis for various studies and research in various parts of the world. The general application of the techniques of timber specimen testing end to move towards a global unification of the outcomes, allowing for a correlations and interchange of data and information as well as the establishment of a structure for use in the cumulative body of important and basic information on the available species of timber in the world. Descriptions of some given tests of strengths make reference to the basic as well as secondary techniques. The timber specimen size has found an extensive usage in evaluating a variety of physical and mechanical properties of different timber species. Objectives Assessment of testing principles for smaller and clearer timber specimens in order to allow for the understanding of timber with regard to their anisotropic nature Analysis of the relationship between strain and stress in materials that are taken into consideration Design of a concrete mix from the given details and information Comparison of the outcomes of the trial concrete mix with the expected on the basis of the provided specifications To carry out research as well as interpretations on particular selected engineering materials Strength test on small clear timber specimens Scope The scope of strength test on small and clear specimen of timbers included and involved; Determination of a variety of strength as well as other properties that are related to strength in the timber through performance of the strength test The technique adopted in the testing exercise represented the steps and procedures used in the evaluation of various physical and mechanical properties, ensuring the control of factors such as the moisture content, size of the specimen, rate as well as the temperature of the loading. Collection and sampling of materials through the use of sample data, graphical illustrations, computation sheets which played an important role in the systemization of the records. Procedure The procedure that was used involved steps in the following order; 1. Preparation of the small clear specimens of timber 2. Photographing of the small clear timber specimens 3. Control of the temperature and the moisture content 4. Recording of the data and information regarding the sapwood and Heart wood 5. Performance of the static bending 6. Performance of compression of the parallel to grain test 7. Usage of the end parallel surfaces in the preparation of the grain test specimens 8. Formulation of a platen sheet of data for the testing of static bending 9. Determination of the testing speed through continuous application of load and taking time duration measurements 10. Taking of load-compression graphs through a specified range of loads and corresponding length 11. Determination of test failure positions 12. Description of the failures resulting from compression Results The results of shear strength test on small clear timber specimens were obtained and graphical represented as shown; Discussion Comparison of hard wood and softwood with regard to strength Lignin plays a significant role in the determination of strength in wood. It is a multi-branched natural polymer whose function is to tightly bind one fiber to another in the wood and therefore ensuring the provision of strength. Even though there are higher concentrations of lignin in the lamella that are positioned immediately between fibers, lignin also exists in the cell wall throughout the fiber. Lignin is considered as a substance with a hydrophobic nature unlike hemicellulose and cellulose. Lignin in the soft wood has got molecules which are not in a position to easily lead to the formation of bonds with one another to aid in the reinforcement of the fiber network. In both the cases of hard wood and softwood, lignin is responsible for the native color that is found in the wood (Ozelton and Baird, 2006). Other that the lignin and the other structural components in wood that are responsible for strength such as the hemicellulose and the cellulose, the hard wood contains organic substances in a very large quantity with a big molecular weight. The comparison between the hard wood and the soft wood with regard to strength also takes into consideration the structural content. For the soft wood, they are considered to have a much lower strength in comparison to the hard wood. This is the case because the content of the structure of the softwoods, which are also referred to as conifers, is composed of rays that are very narrow, longitudinal tracheid meant for conduction but also perform the function of support and also the parenchyma rays. Hardwoods, which are also referred to as the di-cotyledons, on the other hand are much stronger owing to the fact that the structure of their content is composed of strong supporting fibers which play a significant role in the provision of strength. They also have, within their structure, the vessel or elements that aid in conduction, storage parenchyma as well as tall and wide ray which significantly contribute to their higher strength and vary depending on the species (Atkins, 2003). Preparation and testing of concrete trial mix specimen Comparison of the regional mixing with the results obtained The results obtained are subjected to comparison against the regional mixing. The variations in the results obtained are due to the fact that the testing exercise was performed after seven days when it should have been performed after 28 days. The regional mixing is not an exact reflection of the results that are obtained. This is demonstrated by the fact that the results obtained are far much below the expectations of the regional mixing. The preparation and testing of the specimen for use in the concrete trial mix involved the introduction of the preceding designing techniques for use in the determination of a group of proportions of mix. His is meant for the production of the concrete mix with the desired properties in terms or workability and strength. The technique that was employed in this preparation and testing procedure was on the basis of simple classifications for the quality and type of materials as well as the particular cement and aggregates selected (Ceylan, 2009). This was considered as the object used in the formulation of the concrete trial mix specimen as well as the information regarding the subsequent feedback from the trial mix. More trials mix specimens were prepared for the purpose of avoiding delays encountered in the strength testing exercise. The adjustments that were made to the initial proportions of concrete mix differed in accordance with the outcomes obtained from the concrete trial mix tests. They also differed from the designed specifications with regard to the typical classification of materials. The trial mixes are open to courses of action which include the use of proportions of trial mix to produce more mixes, the modification of proportions of trial mix to a small extent in the production mixes as well as preparation of more trial mixes with the incorporation of key alterations to the proportions of the mix (Kempfert and Gebreselassie, 2006). Trial mixes production The production of trial mixes involved the use of design techniques which released the mass for the various materials that were used in the production of the compacted concrete. The batch quantities that were used in the trial mix were obtained directly through the multiplication of every constituent component by the required mix volume. 50 cubic meters was found to be sufficient and which was used in the preparation and carrying out of slump separate measurement. The single components of batch were prepared in kilogram and the trial mixes were prepared in accordance with British standardization requirements which allow for the aggregates to be used in four conditions of moisture and these ones include the air dried, the oven dried, saturated through soaking in water as well saturated dry surface. The performance of the tests carried out on fresh concrete, the formulation of the specimens for testing, the specimen curing and in this case also the testing techniques employed were required to be in accordance with the British standard requirements (Chen, 2007). Procedure The process of design of concrete mix on the basis of provided specifications employed the use of a procedure which included the following steps; 1. The first step was the one dealing with strength and it led to the determination of the cement to free water ratio 2. The second step was concerned with the workability and it brought about the determination of the content of free water 3. The third step involved the combination of the first and the second steps which led to the determination of the content of cement 4. The forth step was concerned with determining the total content of aggregate 5. The fifth step involved selecting the coarse and fine content of the aggregate Design of a concrete mix on the basis of provided specifications The process of coming up with a design for concrete mix on the basis of the specifications provided considers several factors that are significant in the whole process. The factors that are considered in this process of concrete mix design are based on the information that is available of provided in two categories. The first category provides a specification of variables, the specification nominated values as well as the additional data and information that is usually availed to the one in charge of concrete production. This initial category offers details that are useful in combination with the data that is used in reference and which is seen in the form of figures and/or tables. There also exits and intermediate stage which is still part of the first category and this involves the combination of several parameters which actually leads to the formation of the second category. In the second category, the final proportions of units’ are defined with regard to the material mass that is needed for the production of the compacted concrete. The second category in the design of concrete mix involves a process of flow that divided further into five groupings or stages. Every one of these groupings deals with specific design aspect and end up with a final proportion of unit or a very significant parameter. The features of the designed concrete mix are represented in tabulation form as shown; Cement content 409Kg/m3 Specified characteristic strength 40N/mm2 Target mean strength 48 N/mm2 Specified cement strength class 42.5 N/mm2 Aggregate type Coarse uncrushed & fine uncrushed Free water/cement ratio 0.44 Maximum aggregate size 20mm Conclusion In conclusion it is clear that in order to ensure effective and efficient construction of structures, it is important to carry out extensive research as well as the necessary testing procedures. The testing procedures are performed on the building materials with regard to content and structural features such as the strength and composition. It is also important to take into consideration the fact that is important to carry a critical analysis in order to determine whether the soils and the construction materials that are present are fit for the structure design and construction of a given design. This analysis is performed with key consideration of given interpretations of the selected engineering materials. References ATKINS, H. N. (2003). Highway materials, soils, and concretes. Upper Saddle River, N.J., Prentice-Hall. CEYLAN, H. (2009). Performance modeling and evaluation of pavement systems and materials: selected papers from the 2009 GeoHunan International Conference, August 3-6, 2009, Changsha, Hunan, China. Reston, Va, Geo Institute, American Society of Civil Engineers. CHEN, W.-F. (2007). Plasticity in reinforced concrete. Boca Raton, Fla, J. Ross. HUGUES, T., STEIGER, L., & WEBER, J. (2008). Timber construction details, products, case studies. Basel, Birkhäuser. INTERNATIONAL SYMPOSIUM ON NONDESTRUCTIVE TESTING OF MATERIALS AND STRUCTURES, & BUYUKOZTURK, O. (2013). Nondestructive testing of materials and structures proceedings of NDTMS-2011, Istanbul, Turkey. Dordrecht, Springer. KEMPFERT, H.-G., & GEBRESELASSIE, B. (2006). Excavations and foundations in soft soils. Berlin, Springer-Verlag. OZELTON, E. C., & BAIRD, J. A. (2006). Timber Designers' Manual. Hoboken, John Wiley & Sons. Read More