This research was conducted to present state-of-the-art information on fatigue behavior of plain concrete with and without mineral admixtures and to evaluate fatigue characteristics of Class C fly ash concrete under flexural stress. A number of studies have shown that concrete fatigue strength is significantly influenced by a large number of variables, including stress range, loading rate, load history, stress reversal, rest period, stress gradient, material properties, etc. Effects of these parameters on fatigue characteristics of concrete are addressed. In general, endurance of fatigue flexural limit of plain concrete was found to vary between approximately 50 and 70 percent of its static flexural strength. But it can be lower than 50 percent when concrete is tested in water. Experimental investigations conducted in this research revealed that a fly ash concrete mixture with 15 percent cement replacement showed superior performance relative to high-volume fly ash mixtures with 50 percent cement replacement with respect to compressive strength and flexural fatigue strength. However, fly ash concrete mixtures showed essentially the same results when the flexural fatigue strength was expressed as a percentage of the flexural static strength.

With increasing knowledge of the importance of mineral admixtures, many kinds of by-product mineral admixtures have become widespread as an important constituent of cement concrete. By-product mineral admixtures such as fly ash, rice husk ash, and ground granulated blast furnace slag are attracting much attention as materials that not only contribute to the improvement of concrete performance (for example, high strength, high durability, and reduction of heat of hydration) but are also indispensable to the reduction of energy and carbon dioxide generated in the production of cement. Describes the current status of by-product mineral admixtures for concrete and their future outlook.

The environmental condition in the coastal areas of the Arabian Gulf are considered to be very aggressive with regard to concrete durability. The reduction in the useful service life of concrete structures in this region is attributed to an interplay of geomorphic and environmental factors characterized by high concentrations of chloride and sulfate, high ambient temperature and humidity, daily and seasonal variations in temperature and humidity, contaminated groundwater at shallow depths, and contaminated and absorptive aggregates. While the major cause of deterioration is reinforcement corrosion, degradation of concrete due to sulfate attack and salt weathering are not uncommon. Paper presents an overall view of concrete deterioration phenomena in aggressive service conditions, such as the Arabian Gulf, highlighting the role of each degradation phenomenon and the need for further research to produce durable concrete that is economical and has a long service life.

The use of ultra-high-strength concrete for the construction of some types of structural members can be considered if nonbrittle behavior is achieved. Paper introduces reactive powder concretes (RPC) that exhibit ultra-high strength and high ductility at the same time. Compared to conventional concretes, the ductility estimated in terms of fracture energy is increased by one to two orders of magnitude, while the compressive strength values are in the range of 200 to 800 MPa..

Roller compacted concrete (RCC) can possess hardened material properties similar to conventional concrete, but it can also have properties that are well beyond the range that would normally be attributed to conventionally placed concrete. For example, RCC has been used with a modulus of elasticity about 20 times less than normal. Creep rates can be considerably greater than normal. Compressive and tensile strengths can cover a broad range, starting essentially with zero strength and going to high strength levels. The properties that tend to cover a broad range are generally those that are essentially time-dependent. The ability of RCC to have this broad range of properties means that it can also have substantially different toughness and fracture behavior. Lower strength mixtures tend to be much more elastic and have substantial strain capacity after leaving the elastic range. High-strength RCC tends to behave more like conventional concrete with sudden and rapid failure after reaching its elastic limit. Understanding the potential material properties of RCC and utilizing appropriate values in design is crucial to achieving economical and efficient structures. Obtaining the best overall concrete mixture and structural design for applications ranging from dams on variable foundations to pavements is dependent on these properties.