An investigation of Teratak Buluh sand as a foam mortar aggregate material

¹ Civil Engineering Department, Faculty of Engineering, University of Andalas, 25163, Padang, Indonesia
² Civil Engineering Department, Faculty of Engineering, University of Abdurrab, 28292, Pekanbaru, Indonesia
³ Doctoral Student, Civil Engineering Department, University of Andalas, 25163, Padang, Indonesia

^* Corresponding author: elsaeka@eng.unand.ac.id

Abstract

Riau Province has the largest peat soil on Sumatra island. Peat soil has a low bearing capacity and very deep hard soil depth, even in some places up to 16 meters depth. This condition makes the construction of roads on peat soils will experience significant and unavoidable degradation and damage if no special handling is conducted. One of the efforts to overcome the situation in road construction is the use of foam mortar which has been developed by the Road and Bridge Research Centre (PUSJATAN) in 2013 which discovered the Foam Mortar Light Pile technology. This foam mortar is a cement mixture that has a lower density than water. This study conducted further research on finding the ratio of Cement vs. Sand in foam mortar which has a specific gravity smaller than water. The sand comes from Teratak Buluh Village, Kampar Regency, Riau Province and Cement (PCC) comes from Padang City, West Sumatra Province. The cement and sand ratio was varied; 1C:0.7S, 1C:0.8S, 1C:0.9S, 1C:1.0S, 1C:1.1S and 1C:1.2S. Cylindrical samples with a diameter of 10 cm and a height of 20 cm were subjected to a compression test using a modified CBR tool at the 7 day curing time. From the test results, samples at a ratio of 1C: 0.7S and 1C: 0.8S can float in water, with a density of 0.77 tonne/m³ and compressive strength of 901.20 kPa and a density of 0.83 tonne/m³ with a compressive strength of 971.35 kPa respectively.