https://hdl.handle.net/20.500.12852/138 2026-04-06T22:48:34Z https://hdl.handle.net/20.500.12852/2251 Performance evaluation of concrete produced using recycled concrete as both fine and coarse aggregates Paloma, Jonah S. Infrastructure is at the top of list of factors that influence competitiveness due to rapid economic development in cities and has developed concrete into the most significant construction material in the world. This is due to the fact that concrete is produced from natural materials such as sand and gravel; available in all parts of the globe, and that concrete is a versatile material, giving architectural freedom. The production of concrete annually amounts to 1.5 to 3 tons per capita in the manufacturing world, making the concrete industry with all of its suppliers a major player in the building sector. In the last two decades, there has been increasing awareness on environmental concerns in the concrete industry, aiming at reducing the total environmental impact of using natural materials to a minimum, with the emphasis of sustainability on how to deal with the issues of limited resources. A lot of different tools have been developed in order to reduce the environmental impact of concrete and concrete structures and to promote the production of "green concrete". Improvement or rehabilitation of older or ageing infrastructure is also given importance and that includes the demolition of the existing structure to be replaced by a new one. Demolished materials should be utilized productively and should not add to the problem of environment Demolished concrete is one of the recyclable materials but some debris gleaned from demolition sites are left piled on the roads and causes environmental hazard; some are transported to municipal landfill and minimizes the area where fast growing population could build their houses for; and some are additional waste and causes problem on solid waste disposal. Substitution of waste materials in concrete will conserve diminishing resources, and will avoid the environmental and ecological damages caused by quarrying and exploitation of the raw materials for making concrete. To some extent, it will help to solve the problem otherwise encountered in disposing of the wastes. Concrete may be defined as mixture of water, cement or binder, and aggregates, where the water and cement or binder form the paste and the aggregates form the inert filler. In absolute volume terms the aggregate amounts to 60-80 percent of the volume of concrete and is, therefore, the major constituent (Majid, 2000). The aggregate type and volume influences the properties of concrete, its mix proportion and its economy. Conventional concrete aggregate consists of sand (fine aggregate) and various sizes and shapes of gravel or stones (coarse aggregate). Recycled waste materials such as plastic, glass and recycled concrete are potential substitutes as alternative fine and coarse aggregate materials. Tests are needed to be performed in order to investigate the mechanical properties and durability characteristics of the concrete containing recycled constituents. The essential requirement for an aggregate for concrete is that it remains stable within the concrete and in the particular environment throughout the design life of the concrete. The characteristics of aggregate must not affect adversely the performance of the concrete in either the fresh or hardened state. Aggregate parameters such as hardness, strength, and durability are known to be important for engineered-use concrete. The aggregate must be "clean," without absorbed chemicals, clay coatings, and other fine materials in concentrations that could alter the hydration and bond of the cement paste. These potential aggregates are to be evaluated on their compatibility with other materials, concrete properties and economy. Successful utilization of waste material as aggregate depends on ensuring that the properties of concrete will remain unchanged. There is a growing interest in substituting alternative aggregate materials, largely as a potential use for recycled materials. Significant research has been done on many different materials for use as alternative aggregate such as bagasse, plastic, glass, fiberglass, rubber, coconut and palm kernel shells, and recycled concrete. Compressive strength and modulus of elasticity of concrete containing recycled fine aggregate are lower than in concrete containing sand. Substitution of sand for the fines of recycled concrete aggregates does not result in improved strengths. They are used to a limited extent and require some processing. There are lots of information gaps that need to be answered. Among these are the compressive strength of the concrete containing recycled concrete as both fine and coarse aggregates, how is it compared to the compressive strength of conventional concrete, and what are the characteristics of concrete using recycled concrete as both fine and coarse aggregates. It is for these reasons that this study is proposed. Objectives of the Study This study was conducted to test and evaluate concrete produced using recycled concrete as both fine and coarse aggregates. Specifically, this study aimed: 1. To test and evaluate the concrete produced using the conventional and recycled concrete aggregates in terms of the following: a. workability; b. compressive strength; and, c. flexural strength 2. To compare the concrete produced using the conventional and recycled concrete aggregates in different proportions. 3. To determine the acceptability of the concrete produced using recycled concrete aggregates in different proportions. 4. To determine the applicability of the concrete produced using recycled concrete in an infrastructure. Abstract only 2010-01-01T00:00:00Z https://hdl.handle.net/20.500.12852/1560 Mindanao State University - General Santos drainage system Tablo, Diomedes L. Structure is built with a specific purpose. So, it is paramount that a study or design should be made prior to the construction. The ultimate objective of design is to provide, in precise, concise, easy to comprehend form, all the information necessary for construction of the project. Traditionally, designers provide this information in drawing or plans that show what is to be constructed and in specifications that describe materials and equipment to be incorporated into the project. All colleges and universities have one common objective. This is to provide " Quality Education", but Quality Education does not rely solely on classroom instructions but likewise to its environment. Therefore environmental problem must be given great attention in order to make university campuses conducive for learning. Mindanao State University - General Santos City (MSU-GSC) is situated at Barangay Fatima, General Santos City. Its 150- hectare campus with uneven terrain is facing Sarangani Bay. Some of the campus roads are not concreted and drainage system does not exist. In this campus, this special problem entitled; "MSU-GSC Drainage System" will be implemented soon. In Mindanao State University - General Santos City (MSU-GSC), surface runoff or flood is an ordinary scenario during heavy rains. Faculty and students find it hard to transfer from one building to another because of this. Consequently, some students are late in attending their next classes and others may even opt not to attend their classes. For this reason, the researcher finds that this special problem entitled "MSU-GSC Drainage System" is just right and fitting as a solution to the problem. Statement of the Problem Residential areas surrounding MSU-GSC campus have no drainage system. Specifically Barangay Fatima, which is situated at the eastern side of the campus and in much higher elevation. During heavy rains, the accumulated surface runoff from areas, which are in higher elevation moves towards the west following the contours which has lower elevation. Consequently, the route of this runoff passes through the campus and continues to go down in the western side, another residential area is much more affected because of this problem. During rainy days, neighboring areas that are lower in elevation will be flooded. Flood obviously ruins roads, gardens and even some important infrastructures. It is even a threat to everyone's health because it carries bacteria that may cause sickness. This problem has been existing for so long. For this reason, the researcher feels that this problem must be attended to immediately before it causes more damage not only in the campus but to its neighboring areas as well. The researcher came up with this design entitled "MSU-GSC Drainage System" in which seeks if not eradicate, curtails the effects of the surface runoff in this area. Introduction and statement of the problem 2001-01-01T00:00:00Z https://hdl.handle.net/20.500.12852/1531 Economic viability of bagasse and rice hull as composite material for panelboard production Eslit, Yolanda Rubi INTRODUCTION Philippines today presses towards continuing progress as evident in the government's master plan of industrialization and better life for the Filipinos. One major thrust of the government is the Medium term shelter program. Under Republic Act 7279 known as the "Urban Development and Housing Act", policy of the State is to uplift the conditions of the underpriviledged and homeless citizens by making available decent housing at affordable cost (5th Regular Session Congress of the Philippines, 1-2). This entails very great demand for construction materials in order to implement the program. Projected housing units required is 4.2 million nationwide (National Census and Statistics Office 1990-1996 Projections). Aside from the housing units, commercial and industrial buildings, schools, hospitals and others further increase the need for construction materials (Pulido, 1). In Negros Occidental alone, 1993 year—end report of the National Housing Authority (NHA) showed a target of 49,559 housing units with only 31,631 units started construction, this represent only 64% compliance of the target number of housing units (See Exhibit A). The high demand of construction materials poses a great problem. Wood, a priority construction material is suffering accelerated depletion in supply. On the other hand, existing cement manufacturing industries cannot cope up with the demand resulting in insufficient supply with an equivalent high cost and oftentimes delayed completion of construction work. Price of cement in Negros Occidental alone for the first quarter of 1995 shows instability starting from an average of P83/bag in January and soars up to as high as P130/bag in May (See Exhibit B). New technologies at present are geared towards utilization of fibrous agri-wastes into usable alternative materials as an answer to increasing cost of construction materials. One available technology being implemented now is the processing of cement-bonded composite material out of woodwool or bagasse. Although this technology partly solves the present condition of high cost and supply shortage of material but it is still dependent on cement supply. With the aim of providing similar technology for production of low-cost, durable and readily available materials, this study pursues the improvised processing of bagasse-rice hull composite material into panelboards as a plywood and cement-bonded board substitute. The proposed scheme uses waste sugarcane bagasse, as the base material for the panelboard. This approach is commonly used in related process, however, instead of using cement as a binder, a cement substitute will be utilized through pulping of bagasse and kilning of rice hull together with waste lime at specified temperature into ash. The rice hull ash formed usually acquires cement-like properties aside from the "felting" property of pulp bagasse (Baluscang,3). STATEMENT OF THE PROBLEM: With the urgent need of technologies focusing on the processing of alternative construction materials that are cheaper and readily available than cement-bonded boards and plywood, this study aims to address the question: "Will a bagasse-rice hull composite material for panelboard production in the absence of a cement-binder be economically viable?" PURPOSE OF THE STUDY: General Objective: This study is conducted to provide an improvised processing of bagasse-rice hull composite material for panelboards that is economically viable without the use of a cement as a binder. Specific Objectives: This study further aims to a.) utilize available wastes from locally existing industries as raw materials for production. b.) determine feasibility of mass production of the panel boards. c.) find out other possible applications or commercial utilization of the panelboards aside from being a construction material as plywood substitute. Introduction, statement of the problem, and purpose of the study 1996-01-01T00:00:00Z https://hdl.handle.net/20.500.12852/1530 Simplified design of structural timber Rebaldo, Regnier A. This is an instructional manual on the design of structural timber. INTRODUCTION. Timber is a material of construction most commonly used, and one of the most important of which buildings and other structures are built. It is found in many regions of the world. Compared with steel and reinforced concrete, timber is lighter, hence it is easy to transport. Timber may be classified as hard, tough, and flexible. Wood has been used by man since time immemorial. It was probably the only material of which Noah's Ark was built that survived the universal Deluge. It has been used to built the humblest home as well as the most beautiful and lavish palaces of monarchs, sovereigns, and potentates. It is a very useful material of construction in time of peace and in time of war. 1.2 TIMBER, WOOD, LUMBER. From Webster’s dictionary ore gathered the meanings of the following: a. TIMBER is wood, whether the tree or cut and seasoned, suitable for use in building, carpentry, etc. b. WOOD is the hard fibrous substance of trees and shrubs beneath the bark. c. LUMBER (chiefly U.S.A. and Canada) is timber, especially sawed or sliced into boards, etc. d. LUMBERING (U.S.A. and Canada) is the business of getting timber or logs from the forest for lumber. e. LOG is bulky length of a tree trunk or of unshaped timber. f. LOGGING is the business of felling trees, cutting them into logs, and transporting the logs to sawmills or to market. 1.3. CHARACTERISTICS. Timbers are of many kinds, varying greatly in their structural characteristics. Certain kinds of wood are more desirable for some purposes than others. Green timber is heavier than dry or seasoned timber. Seasoned timber is that timber which has been subjected to controlled drying, thereby improving its strength. Green timber has a tendency to warp and to shrink. Moist timber is more flexible than dry timber. Dry timber is lighter than green timber, has greater strength, and works better than green timber in sizing, sawing, and in making tight joints and connections. Soft wood is brittle, while most hardwood is flexible. Hardwoods do not split as easily as soft, woods. Any kind of timber shrinks as it dries, and for this reason, shrinkage should be taken into account in the construction of big buildings and bridges. Since shrinkage in timber can cause a great damage or serious defects, it would be best to use seasoned timber whenever possible. 1.4. PRESERVATION OF WOOD. One of the disadvantages of wood as a structural material is that it is subject to decay. However, if used under proper conditions, the wood in a structure will generally outlive the useful life of the structure itself. Among the causes of decay are the following; (1) alternating wetness and dryness, resulting in wet rot, (2) lack of ventilation, resulting in dry ret, and (3) the destructive action of fungi, worms and insects. In most structures, the effects of these causes are readily controlled. When it is known to the designer that the causes of decay cannot be eliminated, two solutions to the problem are available: (1) to allow the decaying process to proceed and to replace decayed timbers when necessary, in which case an average life of about six to ten years can be expected, or (2) to use timber treated with creosote or some other suitable preservative, in which case the average life is ten to fourteen years more, depending upon the degree of exposure to decay. In the creosote treatment, the timber, after having been properly seasoned, is placed in a closed cylindrical chamber, and steam is introduced to soften the wood fibres. Air and moisture in the timber are then removed by a vacuum pump finally, creosote is injected into the cylinder under pressure, resulting in almost complete penetration of the wood fibres by the creosote preservative. Other simpler and less expensive preservative treatments are also being used. Introduction 1995-01-01T00:00:00Z