Nuclear energy offers a wide range of applications, which include power generation, X-ray imaging, and non-destructive tests, in many economic sectors. However, such applications come with the risk of harmful radiation, thereby requiring shielding to prevent harmful effects on the surrounding environment and users. Concrete has long been used as part of structures in nuclear power plants, X-ray imaging rooms, and radioactive storage. The direction of recent research is headed toward concrete’s ability in attenuating harmful energy radiated from nuclear sources through various alterations to its composition. Radiation shielding concrete (RSC) is a composite-based concrete that was developed in the last few years with heavy natural aggregates such as magnetite or barites. RSC is deemed a superior alternative to many types of traditional normal concrete in terms of shielding against the harmful radiation, and being economical and moldable. Given the merits of RSCs, this article presents a comprehensive review on the subject, considering the classifications, alternative materials, design additives, and type of heavy aggregates used. This literature review also provides critical reviews on RSC performance in terms of radiation shielding characteristics, mechanical strength, and durability. In addition, this work extensively reviews the trends of development research toward a broad understanding of the application possibilities of RSC as an advanced concrete product for producing a robust and green concrete composite for the construction of radiation shielding facilities as a better solution for protection from sources of radiation. Furthermore, this critical review provides a view of the progress made on RSCs and proposes avenues for future research on this hotspot research topic.

This study considers the applications of natural fiber composites in affordable housing projects located in Malaysia with the goal of addressing issues of the thermal comfort. Roof thermal insulation is one of the effective methods that can save cooling energy in places with an equatorial climate especially in Malaysia. The use of recycled products or industrial waste materials is now a potential trend in the industry. Therefore, natural fiber was chosen as a material for the ceiling board in this study. During the day, heat can enter the room from the roof so that insulation material is needed to reduce heat flux by maintaining the temperature of the building. The problems faced by consumers are cost increases due to the use of large amounts of electricity. Besides, asbestos use becoming less frequent because the government has banned its use as a ceiling, side panels, roofing material, asbestos cement-pipes, many types of fireproof and insulation material. The objectives of this study was to determine the mechanical and physical properties of coconut fiber with fire retardant paint as a thermal comfort for ceiling board. The next objective is to study the percentage difference in sodium hydroxide and sodium chloride during the treatment of coconut fiber. The data result is that the fiber is ideal as an insulating material for the house ceiling board because it has a low temperature quality of 0.225W. The water absorption value was as high as 11.20% which is slightly lower than previous studies. Finally, the density test has a value of 74.23 kg / m3 where the fibers are lighter than the other fibers even after immersion with different sodium hydroxide and sodium chloride. In addition, this study achieved a house ceiling that could help reduce the heat entering the house by 0.225W which used only a thickness of 10mm. The use of these fibers does not need the thickness between 20 mm or 40 mm. Therefore, it successfully lowered home electricity consumption in hot weather. It was found that the difference in temperature drop between 0 % and 3 % was 0.4W.

The rapid growth of population has led to increased demand for fast, affordable and quality housing development. Today, the construction industry in Malaysia has shifted from conventional methods to Industrial Building Systems (IBS). The most commonly used IBS component is precasat concrete with lightweight foam concrete. This study focuses on the main component of foam lighweight concrete, which is a partially replacement of cement by sawdust and fly ash. Among the features of lightweight concrete is density below 1800 kg/m3. Therefore, the objectives of this study is to determine the effects of sawdust and fly ash as part of cement replacement in terms of mechanical properties (compressive strenght) and physical properties (water absorption). In addition, this study also determine the optimum percentage of cement replacement by sawdust and fly ash in building material. The percentage of saw dust and fly ash used in this study as a partial replacement cement are 5%, 10%, 15% and 20%. The results show that increasing the percentage of mix propotion will increase the water absorption rate as well as decrease the compressive strenght of strength. Also, the density and compressive strength of lightweight foam concrete will decrease as the percentage of partial replacement cement increases. According to JKR Standard Specification for Building Works that referred in Malaysia, the minimum compression strength of lightweight foam concrete allowed for hollow blocks is 2.8 N / mm2. The results obtained from this study show lightweight concrete blocks using saw dust and fly ash as part of the cement replacement meet the standards and can be commercialized in the industrial building system development.

Exposure of concrete to intense heat will cause deterioration of its strength and durability. Previously, the fire-damaged concrete was repaired using the shotcrete and normal concrete. Recent studies utilize fibre reinforced polymer (FRP) in repairing fire-damaged concrete. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) mostly developed using fine size aggregate, cement, silica fume, super plasticizer and reinforced with steel fibre has an excellent mechanical properties compared to high strength concrete and with an addition of steel fibre in the UHPFRC enhances its ductility behaviour which is not possessed by normal concrete, hence, UHPFRC indicates a promising candidate as repair material to fire-damaged concrete. The aim of this paper is to review on the properties of UHPFRC to be utilized as repair material to fire-damaged concrete structure based on previous research on UHPFRC and fire-damaged structure.