Physico-mechanical and thermal performances of newly developed rubber-added bricks Paki Turgut a , Bulent Yesilata b, * a Harran University, Civil Engineering Department, 63300 Sanliurfa, Turkey b Harran University, Mechanical Engineering Department, 63300 Sanliurfa, Turkey Received 1 January 2007; received in revised form 27 April 2007; accepted 8 May 2007 Abstract The new European energy regulation now considers a high standard of thermal protection in buildings with reasonable energy consumption, satisfactory thermal comfort conditions and low operational costs. A series of significant restrictions on the disposal of used tires in landfills, stockpiles, or illegal dumping grounds are also imposed in recent European Union directives. The potential use of crumb rubber–concrete combination, in favor of these arrangements, for producing a low cost and lightweight composite brick with improved thermal resistance is examined here. The physico-mechanical and thermal insulation performances of these rubber-added bricks are investigated. The obtained compressive strength, flexural strength, splitting strength, freezing–thawing resistance, unit weight and water absorption values satisfy with the relevant international standards. The experimental observations reveal that high level replacement of crumb rubber with conventional sand aggregate does not exhibit a sudden brittle fracture even beyond the failure loads, indicates high energy absorption capacity, reduces the unit weight dramatically and introduces smoother surface compared to the current concrete bricks in the market. Thermal insulation performance is improved by introducing various amount of crumb rubber into the ordinary cementitious mixes. The percentage-wise improvements in thermal insulation performance have varied nearly between 5 and 11%, depending on the amount of crumb rubber used. # 2007 Elsevier B.V. All rights reserved. Keywords: Crumb rubber; Brick; Scrap tire; Concrete; Thermal; Physico-mechanical 1. Introduction The building construction market is one of the most important and highly competitive markets in Europe. The new European energy regulation now considers a high standard of thermal protection in buildings with reasonable energy consumption, satisfactory thermal comfort conditions and low operational costs [1]. The typical U-values required by the national regulations in most European countries have been sharply dropped in the last two decades. This has caused increasing thermal insulation thicknesses in conventional building shells. Consequently, substantial percentage increase in structural cost and reduction in effective living space have been faced. The requirements have increased not only in terms of thermal properties, but also with respect to the environmental impact [2]. An issue that arises out of this activity a search for innovative, environmentally friendly and ready-to-use building composites that combine higher efficiency and quality in the building process with improved thermal resistance. This has set increased demands on the both thermal and mechanical (thermo-mechanical) performances of new building products integrated with various plasters, foils, particles and rubbers [3]. The large demand on building material industry has resulted from the increasing population, leading to a chronic shortage of building materials. The engineers have then been challenged to convert the industrial wastes to useful building and construction materials. Accumulation of unmanaged wastes is today’s one of significant environmental concerns, especially in developing countries. Recycling of such wastes as building materials appears to be viable solution not only to such pollution problem but also to the problem of economical design of buildings. The increase in the popularity of using environmentally friendly, low cost and lightweight construction materials in building industry brings the need for searching more innovative, flexible and versatile composites. The most important aspects of www.elsevier.com/locate/enbuild Energy and Buildings 40 (2008) 679–688 * Corresponding author. Tel.: +90 414 3440020x1094; fax: +90 414 3440031. E-mail addresses: byesilata@yahoo.com, byesilata@harran.edu.tr (B. Yesilata). 0378-7788/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2007.05.002