Fire resistance of lightweight foam concrete by incorporating lightweight bio-based aggregate

Concrete is widely used in the industry due to its effectiveness in terms of cost and strength. In this study, the introduction of bio-based aggregate as coarse aggregate in lightweight foam concrete will be investigated to find a better solution for fire incidents that are commonly happened. As such, lightweight foam concrete (LWFC) has been applied in many buildings especially in non-load bearing wall to enhance thermal conductivity, sound insulation and fire resistance. The aim of this research is to investigate the effect of incorporating bio-based aggregate namely oil palm shell (OPS) into lightweight form concrete in terms of strength properties and fire resistance. Three different concrete mix was designed containing different percentage of OPS aggregate replacement (0, 5, 10 and 15%). From the result, the compressive strength of the LWFC-CTR mixture had achieved the highest compressive strength at 28-day, which is recorded at 3.82 MPa. The fire resistance of LWFC-OPS 15% had showed a positive outcome with improvement by almost 23.5% compared to control mix at 15 minutes. Therefore, the major finding of this research is the incorporation of eco-friendly OPS aggregate has improved the fire resistance of lightweight foam concrete, which can be used as an alternative solution for non-load bearing walls.

Mechanical properties of lightweight foam concrete filler for roadbed of high-speed railway

A high-speed railway has high requirements for line smoothness, and uneven settlement control is the primary factor considered in the design and operation of the subgrade. The emergence of lightweight subgrade structures meets the needs of the development of the high-speed railway. As a kind of filling material with good performance, lightweight foam concrete can effectively reduce the load and excessive settlement of subgrade and effectively reduce the cost of foundation treatment. This paper studied the dynamic characteristics of lightweight foam concrete with different wet densities and water-bearing states under train loading. The effects of wet density and fly ash content on the compressibility, impermeability, and frost resistance of lightweight foam concrete were analyzed in detail. The results show that the lightweight foam concrete still has high residual strength after compression, which is about 60% of its peak strength. Under different mix ratios, the critical dynamic stress of the lightweight foam concrete is generally 0.2–0.3 times the unconfined compressive strength, and the dynamic elastic modulus increases with the increase of wet density and cyclic stress amplitude. With the fly ash content increasing, the volume water absorption of lightweight foam concrete decreases first and then increases, and the critical value of fly ash content is 40%. The frost resistance of lightweight foam concrete gradually increases with the increase of wet density, and the dynamic elastic modulus of the sample with 279 kg·m−3 density lost 41.1% after 20 freeze–thaw cycles. When the content of fly ash is 20%, the frost resistance of lightweight foam concrete is equivalent to that of pure cement.

Integration of Lightweight Foam Concrete Roof, Moving-Air-Cavity, and Solar-Powered Fans for Attic Temperature Reduction

This paper presents a novel cool roof technology system that promotes both passive and active cooling methods in reducing the attic temperature of the building. The project aimed to evaluate the effect of various roof model designs on the heating load to establish the capacity of a cooling roof system by maintaining the thermal comfort level for occupants in the buildings. There are four main components in constructing the cool roof models: 1) metal deck roof, 2) lightweight foam concrete roof, 3) moving-air-cavity (MAC) ventilation, and 4) solar-powered fan. Four small-scale cool roof models were built to evaluate the performance of each cool roof design. The performances of the roof surface and attic temperatures of each designed cool roof models were compared with the conventional metal deck roof. The roof models were conducted indoors by using halogen spotlights. The result of the Roof Design IV with the integration of lightweight foam concrete, MAC, and solar-powered fans has effectively reduced the attic temperature by 6.0°C compared with the normal roof model (Roof Design I). As a result, this integrated cool roof design comprises the ability to enhance the comfortability of occupants toward long-term sustainable development with the utilization of renewable energy to protect the natural environment.

Combustibility of lightweight foam concrete based on natural protein foaming agent

There is an experimental study of samples of monolithic foam concrete “SOVBI” with a density of 205 kg /m3 (grade D200) for combustibility. The evaluation criteria are the following values of combustion characteristics: temperature increment in the furnace, duration of the stable flame burning, sample mass loss. The experimental results show the following values for foam concrete: temperature increment in the furnace of 2 °C, duration of the stable flame burning of 0 s, and sample mass of 24.4%. Thus, monolithic foam concrete with a density of 205 kg/m3 is noncombustible material. It is proposed to use monolithic foam concrete and other lightweight monolithic cellular foam concrete, as a structural fire protection for lightweight steel concrete structures. It, in turn, can increase the fire resistance of external walls and floor structure with the steel frame of cold-formed zinc-coated profiles.