Improving the Properties of the Masonry Produced Using Hemp Stalk with Bark Fibre to Meet Standard Strength and Properties of Energy Conserving Construction Material

This article presents the findings of a research on improving the properties of hemp masonry to meet the standard strength of non-load baring concrete blocks and assess its properties as energy conserving construction material according to specifications declared under the Ministerial Announcement of the Ministry of Energy. Production of hemp masonry used finely chopped hemp stalk with bark mixed with Type 1 Portland cement, sand and water to form 7.5 x 7.5 x 10 centimeters blocks. The ratio by weight between hemp and binder was 1:10 and the property was improved using Al 2 (SO 4 ) 3 , plasticizers, natural rubber latex and polymer. Compression strength, dry density, water absorption, thermal conductivity coefficient, specific heat value and OTTV were tested. The research found that hemp masonry improved using Al 2 (SO 4 ) 3 at 10% by weight of hemp with polymer was the sample with properties within standard limits of non-load baring concrete blocks. The compression strength achieved was 2.79 MPa, dry density 990 kg/m 3 , water absorption 351 kg/m 3 , thermal conductivity coefficient 0.25 w/m°C, specific heat 1.12 kJ/kg°C and the highest OTTV of 45 w/m 2 was calculated for the southeast wall. This was lower than the minimum standard for masonry of energy conserved office building. Therefore, the masonry produced using hemp stalk with bark has the strength comparable to non-load baring concrete block and has the quality to protect heat from outside which is good for energy conservation construction practice.