Effects of elevated temperature on high performance concrete incorporating of metakaolin and garnet

Durability has become one of the major indicators to dictate a good quality of concrete. Rapid growing in construction leads to the demand of high strength concrete which can bear high stress and high resistance towards any hazard and harsh environment thus providing a safe structure. High performance concrete (HPC) has been identified as one of the advanced types of concrete that can fulfill the criteria. Hence, in this study resistance towards elevated temperature of HPC incorporating 10% of metakaolin as part of cementitious material and 50% of garnet as part of replacement of fine aggregates were investigated. Samples of HPC with metakaolin and garnet (HPCMG) and HPC with metakaolin (HPCM) were exposed to different heating temperature of 200°C, 400°C, 600°C and 800°C for duration of one hour. The changes of physical in color and the appearances of cracks in all samples were closely observed. In addition, compressive strength tests according to BS1881-116:1983 and percentage of weight loss for all the samples were also monitored in this study. Results showed that as the temperature increased, significance losses of compressive strength were detected for both HPCMG and HPCM. At the temperature of 800°C, HPCMG degenerated 86.8% of its strength compared to 71.8% for HPCM. As temperature increased, weight loss of HPCM indicated higher reading compared to HPCMG. Major changes of the physical appearances were also detected in both HPCM and HPCGM samples such as cracks and increment in gap width on the samples. This summarized that HPCM has better fire resistance compared to HPCMG

Overview on the theoretical prediction of shear resistance of steel fibre in reinforced concrete beams

This paper presents the experimental results and theoretical study on the shear strength of reinforced steel fibre concrete beams. Failure of reinforced concrete beams in form of diagonal tension failure has been very complex to predict accurately. The inclusion of steel fibre substantially increased the ductility of the concrete and improves the shear behaviour of the beams. Due to bridging effects provided by the steel fibre, it reduces the brittle shear failure of plain concrete. Previous test data were categorized by the influence of steel fibre in reinforced concrete beams. All test results showed that steel fibre has a significant influence on the ultimate shear strength of reinforced concrete beam and control the development of crack propagation. A discussion on the contribution of steel fibre on the shear strength is also presented, with reference to the past researcher formula and RILEM provisions. The shear strength prediction for steel fibre reinforced concrete beams were compared with those obtained by the experimental test. The comparison shows that the mean value of the ratio of the experimental ultimate shear strength to predicted ultimate shear strength for the beams tested was about 0.59 to 1.96

Housing affordability stress among generation y in Johor Bahru, Malaysia

Nowadays, a significant number of households are still unable to afford to buy their own houses due to the high prices on the market. However, household income is also at odds with the market price of housing. Housing affordability stress, therefore, refers to a situation in which households spend only 30% of their income on housing costs. Therefore, two research objectives were set. The first objective is to identify factors affecting the stress of housing affordability between Gen Y. The second objective is to examine the relationship between income and house prices affecting the stress of housing affordability. Data are collected through secondary sources and information provided by respondents through questionnaire surveys. The data are then analyzed using the Social Sciences Statistical Package (SPSS). Method of data analysis includes Frequency Analysis, Likert Scale Analysis, Cross Tabulation Analysis and Pearson Chi-Square Analysis. The results show that 67 respondents still haven't had their own house and they live with their families or still rent a house. Just 33 respondents own their own house and most purchase just RM200,000 to RM250,000 one-storey terrace homes. The high house price provided, household income is not parallel to the current economy and high down payment and other charges are three factors that strongly influence the housing affordability pressure