engleski

The effect of different aggregate grading on the properties of normal and lightweight pervious concretes

Pervious concrete is a special type of concrete with increased amount of voids which achieves its high rain and storm water permeability. In recent years, pervious concrete has a significant role in building technology. Its most important environmental benefits are controlling storm water runoff, recharging groundwater supplies, reducing water and soil pollution and mitigating the urban heat island effects. The use of lightweight aggregates can achieve further improvement of pervious concretes and their environmental impact. Increased use of these types of concrete could significantly contribute to the improvement of sustainable construction, but also to the ecology and maintenance of clean water. However, only few researches on lightweight pervious concretes have been performed [1-4]. Further researches on the use of lightweight and waste materials in pervious concrete are most welcome. In this study, the properties of pervious concrete made of normal weight and lightweight aggregate have been examined. Limestone aggregates and lightweight aggregates made of expanded clay and glass were used in the mixtures. Different grading and maximal grain size of coarse aggregates were varied to analyse the influence of a different pore structure. The amount of binder was adopted as 350 kg per cubic meter for all mixtures. The water content was adjusted to obtain the appropriate stable consistency. Properties of pervious concrete mixtures in fresh and hardened states were considered. All mixtures were casted in cylindrical and cubic moulds and cured for 28 days. Porosity, permeability, density, compressive and tensile strength of pervious concretes were evaluated in hardened state. The experimental results were compared to obtain an optimal mix design of normal and lightweight pervious concrete in terms of sufficient strength and permeability. Finally, main conclusions of this research are given.

pervious concrete ; lightweight aggregate ; permeability ; strength properties

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