comparison of mix-design and compressive strengths of leca, scoria and perlite lightweight concretes with using twist-off method

regarding the increasing demand for lightweight concrete especially lightweight structural concrete, and safety requirements underlined in 2800 iranian standard, research to achieve the optimized results in lightweight concrete production seems inevitable. since, one of the commonly used methods for producing the light eight concrete, utilizes the light weight aggregates with significant role in the concrete strength, proposing the optimized mix-design for the light weight concrete appears to be important. in this paper, concretes made from leca, perlit and scoria, are investigated. by using the light weight concrete, 120 cubic specimens were constructed and tested by compression and twist-off methods. in addition to the relationships between the results of compression tests and twist-off method, effects of the additives on the properties of the lightweight concretes are presented.