Effect of Adding Used-Foundry Sand on Hot Asphalt Mixtures Performance


Highway material researchers have been investigating the use ofbyproduct materials such as used-foundry sand as a fine aggregate and mineral filler in asphaltic concrete mixtures to replace the traditional asphalt mixes by new one contain this type of sand. This researchshow a study using of used-foundry sand as an alternative to filler and fine aggregate in hot asphalt mixture, aims to minimize the environmental effect caused by this waste materials. To evaluate mechanical properties, the mixtures were designedby Marshall method which contain the used- foundry sand and determine indirect tensile strength ratio and then compared with hot asphalt mixtures contained of two types of filler(ordinary cement and limestone dust).The results showing that the reuse of foundry sand in the mixtures of hot mix asphalt as a partial replacement of fine aggregate that retained on sieve No 200 and a total replacement of filler material is viable and can be used in asphalt mixtures production. The hot asphalt mixtures containing of used-foundry sand with cement filler type improved the moisture sensitivity performance as characterized in indirecttensile strength ratio. Furthermore, that theresults obtained from Marshall stability test indicate maximum Marshall stability obtained for mixtures with cementand used-foundry sand more than these stabilities for mixes with used-foundry sand and lime stone dustas a filler were (15.3, 12.5 and14.1) respectively .