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Abstract: The volume of polymeric wastes like tyre rubber and polyethylene terephthalate bottles (PET) is increasing at a fast rate. An estimated 1000 million tyres reach the end of their useful lives every year and 5000 millions more are expected to be discarded in a regular basis by the year 2030. Up to now a small part is recycled and millions of tyres are just stockpiled, landfilled or buried. As for PET bottles annual consumption represent more than 300,000 million units. The majority is just landfilled. This paper reviews research published on the performance of concrete containing tyre rubber and PET wastes. Furthermore it discusses the effect of waste treatments, the size of waste particles and the waste replacement volume on the fresh and hardened properties of concrete. [Copyright &y& Elsevier]

Abstract: The alkali activation of alumino-silicate materials is a complex chemical process evolving dissolution of raw materials, transportation or orientation and polycondensation of the reaction products. Publications on the field of alkali-activated binders, state that this new material is likely to have high potential to become an alternative to Portland cement. While some authors state that the durability of these materials constitutes the most important advantage over Portland cement others argue that it’s an unproven issue. This paper presents a review of the literature about the durability of alkali-activated binders. The subjects of this paper are resistance to acid attack, alkali–silica reaction, corrosion of steel reinforcement, resistance to high temperatures and to fire, resistance to freeze–thaw. Special attention is given to the case of efflorescences, an aspect that was received very little concern although it is a very important one. [Copyright &y& Elsevier]