ICE - Institution of Civil Engineers - Virtual Library

Structural insulated panels (SIPs) are typically formed from a thick layer of polystyrene foam sandwiched between two layers of oriented strand board. They have improved insulation qualities due to reduced cold bridging effects and satisfy all other building regulations. They are also durable if a stringent manufacturing procedure is used. SIPs are a sustainable and cost-effective alternative to traditional timber-frame construction.

Bonded-in technology provides rapid and reliable solutions for the connection, reinforcement and repair of timber structures. This briefing describes how fibre-reinforced plastic pultruded rods are bonded into over-sized holes or slots in timber, using room-temperature cure epoxy adhesives, to achieve coherent timber-to-composite interfaces. The results of pull-out tests are reported which confirm the integrity of the pultruded rod-to-timber interface. Examples of timber connections, reinforced beams and the repair of timber bridges are examined, and a comprehensive list of research references are included which underpin bonded-in technology for structural timber.

Concerns about climate change have heightened interest in sustainable construction materials. Ground granulated blast-furnace slag offers civil engineers a high-quality, environmentally-friendly material, which can replace much of the Portland cement used in concrete. This article looks at its manufacture and environmental impact and gives examples of its use.

This paper summarises investigations that were conducted to assess the durability of plain and blended type II Portland cement exposed to marine tidal environments. In this research the performance of cement paste and concrete mixes incorporating 7 and 10% silica fume as a cement replacement was investigated in three exposure conditions with seven days’ initial curing in potable water. The performance of plain and blended cements was evaluated by monitoring changes in compressive strength and capillary absorption. The results show that plain type II Portland cement performed better than blended silica fume cement under cyclic wetting and drying conditions. Silica fume specimens under cyclic wetting and drying conditions in simulated seawater exhibited higher strength loss in comparison with plain type II Portland cement when cured under potable water. In addition, the greater the silica fume amount used in the mixes, the more the capillary water absorption under tidal zone exposure and/or under wetting and drying simulation. Further, the ternary-blended ground granulated blast-furnace slag mix was the worst-performing mix in all exposure conditions. An extended initial curing time is recommended for these types of mixes.

Self-compacting concrete (SCC) is increasingly being used in precast concrete sewer pipes, water treatment facilities, industrial floors and foundations that are susceptible to biogenic and/or chemical sulfuric acid attack. Since the mixture design of SCC is different to that of normal concrete, the durability of SCC in such applications needs to be evaluated. In particular, SCC can incorporate proportions of limestone filler and different combinations of aggregates, which is believed to alter its resistance to sulfuric acid. Hence, this study aimed to investigate the resistance to sulfuric acid of various SCC mixtures incorporating different limestone material types, proportions and combinations. The study comprised 12 weeks of immersion of test specimens in 1, 3 and 5% sulfuric acid solutions with a maximum pH threshold of 3, 2 and 1, respectively. The study revealed that the resistance to sulfuric acid of SCC incorporating limestone materials was dependent on the degree of solution aggression. While limestone filler contributed to increasing the resistance of SCC to the moderately aggressive solution (3% sulfuric acid), it accelerated the rate of mass loss in the highly aggressive solution (5% sulfuric acid). The effect of fineness and particle size of limestone and the kinetics of corrosion reaction on the resistance of SCC to sulfuric acid was also highlighted in this study. Microanalysis conducted upon test termination elucidated the damage mechanisms, and it was shown that the change in compressive strength after exposure to sulfuric acid solutions was not a proper indicator for the surface deterioration of SCC in acidic media.

Members of the Construction Materials editorial advisory panel provide overviews of their areas of expertise, highlighting recent and forthcoming developments likely to affect engineers and others working in the field of construction materials.