Abstract. Global warming can be defined as a gradual increase in the overall temperature of the earth's atmosphere. A lot of research work has been carried out to reduce that heat inside the residence such as the used of low density products which can reduce the self-weight, foundation size and construction costs. Foamed concrete it possesses high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength and excellent thermal insulation properties. This study investigate the characteristics of lightweight foamed concrete where Portland cement (OPC) was replaced by hollow glass microsphere (HGMs) at 0%, 3%, 6%, 9% by weight. The density of wet concrete is 1000 kg/m3 were tested with a ratio of 0.55 for all water binder mixture. Lightweight foamed concrete hollow glass microsphere (HGMs) produced were cured by air curing and water curing in tank for 7, 14 and 28 days. A total of 52 concrete cubes of size 100mm x 100mm x 100mm and 215mm x102.5mm x 65mm were produced. Furthermore, Scanning Electron Microscope (SEM) and X-ray fluorescence (XRF) were carried out to study the chemical composition and physical properties of crystalline materials in hollow glass microspheres. The experiments involved in this study are compression strength, water absorption test, density and thermal insulation test. The results show that the compressive strength of foamed concrete has reached the highest in 3% of hollow glass microsphere with less water absorption and less of thermal insulation. As a conclusion, the quantity of hollow glass microsphere plays an important role in determining the strength and water absorption and also thermal insulation in foamed concrete and 3% hollow glass microspheres as a replacement for Portland cement (OPC) showed an optimum value in this study as it presents a significant effect than other percentage.

Coconut Shell Powder were obtained from coconut shell that had been discarded and grinded until it become in a form of powder. This study were conducted to determine the chemical and physical properties of coconut shell powder to be used as a filler inside concrete. In order to do that, an experimental setup of X-Ray Fluorescence (XRF), Particle Size Distribution, Scanning Electron Microscopic (SEM), Density, and Specific Gravity were conducted. The coconut shell powder consist mostly carbon (C) and potassium oxide (K2O). The presents of silicon dioxide (SiO2) is crucial in order to be mix with concrete. The size of the coconut shell is ranging from 600μm and below. From all the testing, it is show that the coconut shell powder can be use in mixing with concrete as a filler.

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Abstract. Nowadays, advanced development and sophisticated new technology have led to various types of environmental pollution such as water, air, land, thermal pollution and so on. Recently, however, noise pollution is becoming one of the major threats to the world especially in urban areas where it adversely affects the quality of life of the public. In Malaysia, the Department of Environment has identified that the average transportation noise levels in major cities in peninsular Malaysia are 71.6 dB (A) and 70.4 dB (A) during the day and night respectively. The noise is usually emitted by airplanes, trains, vehicles, motorcycles, trucks and etc. Even though rail transport requires less energy and emits less hazardous substances, it has contributed to noise pollution issues and several health hazards among urban inhabitants such as deafness, nervous breakdowns, mental disorder, heart troubles, high blood pressure, headaches, dizziness, inefficiency and insomnia. Therefore, many studies attempt to reduce noise pollution by applying noise barriers at noise polluted areas via various approaches. This paper aims to explore the effectiveness of noise barriers using noise absorption performance due to several factors such as type of absorbent materials, material thickness, density, porosity and design. This research has found that the thicker the specimen and the denser the absorbent material, the better the sound absorption performance. Besides that, barrier design also plays a major role in determining its effectiveness, where the effectiveness of noise barriers should be high and long enough to break the line-of-sight between the sound source and the receiver. There are several methods that can be used to measure the effectiveness of noise barriers such as the Adrienne Method (in-situ measurement method) and impedance tube method (laboratory measurement method) to measure the acoustic absorption. Nevertheless, the impedance tube measurement method provides the most precise results with the least measurement uncertainty as it only required small samples of the material.

Discarded scrap tyres have become one of the major environmental problems nowadays. There has been increasing public worry about the mining of natural resources in recent years. In order to minimize the consumption of natural resources, rubber ash has been postulated as a potential material for partial replacement of sand in concrete materials especially for applications which are subjected to impact and vibration such as road and bridge construction. Thus, it contributes to the development of the construction industry in a sustainable way. This paper mainly emphasizes on the use of rubber ash from waste tyres in cement mortar. 100mm cubic specimens were produced by adding rubber ash volume ratios of 0%, 3%, 5% and 7% as sand replacement in M30 quality cement mortar. A compressive stress test and a density test were conducted at the end of 7, 14, and 28 days. The result shows that 5% is the optimum value for sand replacement in the cement mortar. Therefore, rubber ash is acceptable to be used as sand replacement.

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Waste tires pose significant health and environmental concerns if not recycled or discarded properly. At the same time, natural sand is becoming scarcer and costlier due to its non-availability. Waste tires as fine aggregate can be an economical and sustainable alternative to the natural sand. Recent years, the interest on recycling waste tires into civil engineering applications by the researchers has increased. In this research, the chemical and physical properties of the tires rubber ash and the natural sand have been analysed. The densities of the rubber ash are lower than the natural sand. Rubber ash had finer particle size compared to the natural sand. Almost all chemical in the natural sand had in rubber ash with the additional sulphur trioxide and zinc oxide in the rubber ash, made the rubber ash better than natural sand. Rubber ash seems to be a suitable material to use in concrete as sand replacement.

Abstract. The cost for producing concrete has been increasing steadily. Therefore, the demand for using agricultural waste as a replacement or admixture inside concrete is also increasing gradually. Many researchers are doing research on agricultural waste such as palm oil, corn cobs, rice husks and coconut shells. Agricultural waste is increasingly being utilized in cement, concrete and other construction materials and provides numerous indirect benefits such as reduction in land fill cost, saving energy and protecting the environment from possible pollution. The aim is to produce concrete with improved properties at a lower cost and to maintain environmental sustainability. In this review paper, the suitability of coconut shell for concrete cool wall panels will be the main focus. Coconut shells can be used as aggregates in concrete. The characteristic properties of coconut shell concrete such as workability, bulk density, compressive strength, flexural tensile, water absorption and thermal performance were reviewed in this paper. This paper attempts to answer whether coconut shell is suitable to be used in concrete to produce a concrete cool wall panel in order to reduce heat transfer inside a building.