Journal of American Science, 2011;7(2) http://www.americanscience.org http://www.americanscience.org editor@americanscience.org 115 Evaluation of the Effects of Bagasse on Tensile and Compressive Strength of Lightweight Concrete Mojtaba Labibzadeh 1 , Mehdi Nasirifar 1 , Amin Khajehdezfuly 1 1 Department of Civil Engineering, Faculty of Engineering, Shahid Chamran University, Ahvaz, Iran Labibzadeh_m@scu.ac.ir Abstract: Mechanical characteristics of lightweight concrete contained bagasse, including splitting tensile and compressive strength have been examined. Bagasse as an agricultural waste was obtaining in the form of small wood chips after extracting cane sugar in the Khouzestan state of Iran. In this research, at first a fixed mix design was considered according to ACI-21. Then some samples were prepared corresponding to the above mentioned design code and by inserting 20,30,40 and 50% bagasse as a replacement for aggregates in concrete mixture and consequently these samples were tested. The results showed that by increasing of the content percentage of bagasse, compressive strength decreased and this decrease for concrete containing 20% bagasse is about to 36%.The concrete containing 20% bagasse has more splitting tensile strength in compared to normal concrete approximately up to 13%. Finally, based on the obtained findings, it can be concluded that concrete with 20% bagasse could be introduced as an alternative lightweight concrete regarding to its lower unit weight and higher splitting tensile strength. [Mojtaba Labibzadeh, Mehdi Nasirifar, Amin Khajehdezfuly. Department of Civil Engineering,Shahid Chamran University, Ahvaz, Iran. Journal of American Science 2011;7(2):115-120]. (ISSN: 1545-1003). http://www.americanscience.org . Keywords: Bagasse; Lightweight concrete; Compressive strength; splitting tensile strength 1. Introduction Using of lightweight concrete as an alternative to normal concrete in construction can decrease the building’s dead load as well as the force exerted on the structure due to earthquake excitations and the resultant collapse weight of the building if it falls down (Liu, et al., 1995). The use of lightweight aggregate concrete (LWC) can lead to reduction in costs of the both superstructures and foundations. Furthermore, the better thermal insulation, the greater the fire resistance and the substantially equivalent sound-proofing properties make it preferable with respect to normal weight concrete (NWC) to use in building structures (Cavaleri, et al., 2003). In bridges and other precast construction, the lightweight concrete helps to reduce the costs of shipping and crane capacity, inclusive considering the higher cost of the aggregates (Tito, et al., 2010). Lightweight concrete provides high strength-to-weight ratio and is ideal for long span structures, super high-rise buildings and offshore floating structures. For example, in Norway (LWC) has been successfully used in offshore structures for oil drilling platforms, storage tanks and vessels (Koh, et al., 2008). On the other hands, development of industries and stepping towards industrialization requires performing comprehensive research on consuming agricultural, mineral and industrial wastes in construction in order to decrease environmental pollutants. Bagasse is one of these agricultural wastes. It is a by-product of cane that is produced in the form of small wood chips after extracting cane sugar. At present, about one million tons of bagasse is produced in Iran annually which leads to environmental and retrieving management problems. So far, no significant research has been conducted on using bagasse in making concrete in Iran. Thus it is felt that such a study could be useful in this field. Ganesan et al., (2007) studied on the effects of using bagasse ash as a replacement for cement in making concrete mixture on physical and mechanical characteristics of hardened concrete. They found that the bagasse ash was a useful mineral that its optimal replacement amount for cement in concrete mix was approximately 20%. Another research on using bagasse ash as a replacement for cement in concrete manufacturing has been conducted by Chusilp et al., (2009). He and his colleagues evaluated compressive strength, permeability and temperature characteristics of obtained lightweight concrete containing bagasse ash. They concluded that the optimal amount of bagasse ash which could be replaced with cement in preparing concrete would be about to 20% by weight of cement and increasing this ratio to 30% caused lower permeability and compressive strength. They also found that the maximum temperature rise of concrete containing 10-30% bagasse ash was less than that of control concrete so that an increase replacement ratio led to decrease in equivalent temperature rise. Most of the researches on bagasse in concrete were associated with using it as a replacement for cement in order to improve concrete mortar. In this study, fibers of bagasse are used, in a