%0 Journal Article %T Investigation of engineering properties of biological lightweight concrete and evaluating the air-entrained protective effect on bacteria performance improvement %J Amirkabir Journal of Civil Engineering %I Amirkabir University of Technology %Z 2588-297X %A Dinarvand, Paria %A Rashno, Alireza %D 2022 %\ 10/23/2022 %V 54 %N 8 %P 3155-3178 %! Investigation of engineering properties of biological lightweight concrete and evaluating the air-entrained protective effect on bacteria performance improvement %K Biological lightweight concrete %K air-entrained concrete %K Bacteria %K Durability %K Curing Environment %R 10.22060/ceej.2022.19671.7229 %X Regarding the particular position of lightweight concrete in the world's construction industry, producing high-quality lightweight concrete, which is based on creative materials, has become one of the fundamental aspects of this ever-developing industry. Microbial calcite precipitation induction is known as a new environmental friendly strategy. Although the main goal of developing biological concrete has been crack healing, achieving this goal must not only be without negative effects on the mechanical properties and durability of concrete, but also through knowing and testing the key effective parameters, a biological concrete with the ideal engineering properties can be obtained that is distinguished among the other typical kinds of concrete. In this study, to produce lightweight concrete with desirable durability and resistance, the technique of using bacteria in concrete has been enjoyed. Small concrete pores, alkaline environment, inaccessibility to nutrients and enough oxygen are the basic challenges of using biological minerals in concrete. Therefore, the air-entrained has been used as a protective approach to enhance bacteria durability and preserve colonies. The results of the tests conducted show that calcium carbonate precipitation resulted from the metabolic activity of microorganisms has resulted in the increase of mechanical properties and improved durability of lightweight concrete. Also, air-entrained as an effective factor has had a fundamental role in preserving durability and improving bacteria performance. The use of bacteria in concrete has led to an increase of 19.8% in compressive strength and 63.9% in electrical resistance. Also, the maximum reduction of water absorption and reduction of chloride ion penetration in the biological sample was 62.7% and 40.7%, respectively. %U https://ceej.aut.ac.ir/article_4713_d6303902543f0b74a51e0bd5cf1248de.pdf