The purpose of this study is to investigate the effect of high Temperatures on the mechanical properties of lightweight geopolymer concrete made of palm oil industrial waste materials known as palm oil fuel ash (POFA) and oil palm shell (OPS) as binder and coarse aggregate in geopolymer concrete would give an added advantage in both environmental and economic aspects with alkaline activator to binder (AK/B) ratios of 0.3 and 0.6. For each (AK/B) ratio, POFA was replaced with 0%, 10%, 25%, 50%, and 100% of fly ash (FA). To that purpose, the mechanical properties of OPS geopolymer concrete (OPSGC) produced using POFA, FA, and OPS are examined in terms of compressive strength, splitting tensile, and flexural strength. To determine the compressive strength loss for each mixture, the geopolymer concrete samples were subjected to high Temperatures of 200°C, 400°C, 600°C, and 800°C. The test findings showed that increasing the alkaline activator to binder (AK/B) ratio at 3, 7, and 28 days increased the compressive strength. Generally speaking, exposure to Temperatures above 200°C causes the OPSGC to increase in compressive strength. Following exposure to Temperatures as high as 400 °C, the OPSGC's strength began to decline. AK/B ratio of 60 are less affected by high Temperatures than mixes made with an AK/B ratio of 30. The miture of 25% POFA content, AK/B ratio of 0.6, and oven curing provided the maximum strength of 30.9 MPa and Less strength loss compared to other options.

Fire accidents are inevitable and it is one of the significant hazards, which causes loss of life and valuables. The present investigation focused to study the influence of fibers on shear strength of concrete exposed to Elevated Temperature as per ISO 834. The fibers used in the study were Basalt, Carbon, Glass, Polypropylene and Poly vinyl alcohol. M20, M30, M40 and M50 grades of concrete were used for the investigation. The results revealed that the shear strength is declined with increase in Temperature. The shear strength is enhanced by the addition of fiber in the reinforced concrete beams exposed to Elevated Temperature. Carbon fiber reinforced concrete specimens exhibited better residual shear strength than the other specimens. Addition of carbon fiber and basalt fiber in concrete reduced the micro cracks in the specimens exposed to Elevated Temperature. Addition of polypropylene fiber and poly vinyl alcohol fiber reduced the spalling but the crack propagation was not prevented in the specimens exposed to high Temperatures.

In the event of sudden fire break out, the concrete elements such as columns, beams etc. are subjected to extreme Temperatures. The assessment of their performance after fire becomes necessary to decide upon its fitness and required repair measures. Hence, it is important to understand the changes in the concrete properties due to its exposure to extreme Temperatures. It is important to know the effect of Elevated Temperature on the properties of concrete. This paper investigates the effect of sustained Elevated Temperature on the properties of ordinary concretes of M40 grade, containing different types of cements and cured by two different methods. The specimens were heated to15°C, 30°C and 45°C for 1 hour duration in a muffle furnace. They were tested for compressive strength after air cooling to the room Temperature. The variables considered in the study include type of cementing material, Temperature and method of curing. The comp. strength of concrete and weight of concrete decreased with increasing Temperature. Specimen subjected to conventional water curing performed relatively better than those of membrane curing.

Effects of Temperature on properties and behavior of a 20 vol % particulate SiC reinforced 6061 aluminum alloy and 6061 unreinforced Al alloy were investigated. Yield strength and elongation to failure were measured as a function of test Temperatures up to 180^oC. In addition, the effects of holding time at 180^ oC on tensile properties and fracture mechanisms of the materials at this Temperature were studied. The behaviors of the materials were characterized by using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDS), X-ray diffraction (XRD), atomic absorption (AA), hardness measurement and image analyzing (IA). The results show that an increase in Temperature leads to a decrease in the yield strength and increase in the elongation to failure of the materials. On the other hand, while increasing holding time at 180^oC produces an increase in the elongation to failure of the unreinforced alloy, it reduces the elongation to failure of the composite. It was also observed that reduction in yield strength with increasing holding time at 180^oC was faster for the composite material compared to the unreinforced alloy. The results from SEM, XRD, EDS, IA and hardness tests indicated that some chemical reactions had taken place at the interface between the reinforcement and the matrix alloy during holding the specimens at Elevated Temperature. Therefore, different trend in elongation to failure of the unreinforced alloy and the composite material with holding time at Elevated Temperature could be attributed to development of chemical reactions between the reinforcement and the matrix alloy at the interface.