A study on improvements of some properties of lightweight aggregate concrete blocks used in agricultural buildings

In Turkey, the usage of lightweight aggregate concretes is increasing during last years, due to its superior properties compared with traditional construction materials such as stone, adobe and brick specially in view of unit weights, thermal isolation and freezing-thawing durability properties. Turkey has a great potential sources of natural lightweight aggregate used in lightweight concrete blocks. The objectives of this study were to determine physical and mechanical properties of lightweight aggregate concretes and to compare them with these of traditional concretes, and to study on improvements of some physical and mechanical properties of concrete blocks used in structural walls of agricultural buildings in rural areas. Lightweight aggregates obtained from Erciş (Van) and Pasinler (Erzurum) and mixed tuff and natural sand were used in lightweight concrete blocks production. Properties of these aggregates were determined, natural and adjusted grading combination of these aggregate were used with 150, 200, 250 and 300 kg/m3 dosage for concrete blocks. Measured physical and mechanical properties of concrete blocks, indicated that 28 day compressive strength varied from 12.1 to 26.3 kgf/cm^, oven dry unit weight between 575 and 751 kg/m3, thermal conductivity 0.135 and 0.192 kcal/mh°C, compressive strength after freezing and thawing 12.1 and 26.3 kgf/cm^, and water absorption values between %18.6 and %27.6. It was determined that tuff mixed lightweight concrete blocks had lower unit weight and thermal conductivity than lightweight concrete blocks mixed with natural sand. There were no significant differences between concrete blocks produced by natural aggregates and aggregates adjusted by grading. Lightweight aggregate concrete blocks reached the minimum compressive strength, which is specified in standards, at 250 kg/m3 cement dosage. Freezing and thawing cycles increased compressive strength and water absorption values of concrete blocks. It was clearly stated that if the local concrete blocks producers take into consideration our results, they will improve some properties of their products. In conclusion, lightweight concrete blocks produced by lightweight aggregate, which have a huge potential in the Eastern Anatolia Region and have suitable properties, can successfully be used in local agricultural buildings. 2002, 164 pages Key words : Lightweight aggregate, pumice, tuff, lightweight concrete blocks, agricultural buildings, physical properties, mechanical properties