EXPERIMENTAL STUDY ON CHARACTERISTICS OF POROUS CONCRETE AS A MATERIAL PAVEMENT FOR ROADS WITH MEDIUM TRAFFIC

• Main Author: Realita Purba, Henny
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/80504
• Institution: Institut Teknologi Bandung

Porous concrete is a concrete mixture as an innovative approach to control, manage and treat runoff of rainfall and has a zero slump which formed from cement, coarse aggregate, a few or no fine aggregate, additives and water. The main objective of this research is to determine the characteristics mixture of porous concrete that can drain water from the road surface through the pores of the concrete and applied as pavement structures for roads with medium traffic volumes. The physical properties of the aggregate as a concrete mixture were tested and analyzed referring to the general specifications of Highway 2018 second revision. Variation of coarse aggregate used were aggregate with diameters of 15-30 mm, 10-20 mm, 5-10 mm and 3-5 mm, variation percentage of fine aggregate and additive. Based on the this research, it was found that the highest compressive strength were obtained in the mixture of third variation of 28 MPa and 2,21 MPa respectively where third variation used an aggregate of 5 – 10 mm in diameter, 0% of fine aggregate, 0,22 of water-cement ratio and 1,2% of superplasticizer. Meanwhile, the highest infiltration rate achieved at fourth variation was 9,64 mm/sec. The effect of a low water-cement ratio (0,22) in third variation can increase the value of compressive and flexural strength of porous concrete because it contents more cement to binding aggregate, but the high cement content will reduce the pore of the concrete so that the rate of infiltration decreased. If the water-cement ration is reduced to 0,2 as in fourth and fifth variation, the concrete mixture becomes heterogenous because there wasn’t enough water for hydration process and the workability was quite low. A large size of aggregate with uniform gradation will increase the porosity of concrete, but this will reduce the strength of the concrete because too many voids and the mixture was hard for compacting. The percentage of fine aggregate with less than 15% doesn’t have a significant effect on the strength of the porous concrete. This is shown in third variation which doesn’t use fine aggregate but can produce the highest strength compared to fourth variation which uses 15% of fine aggregate. The effect of low ratio aggregate-cement in first variation has a significant effect on the strength of the porous concrete because a low ratio aggregate-cement produces a large amount of cement paste that envelops the aggregate so that the bond between the aggregate and the paste is getting stronger. However, this is opposite to the porosity because the paste will cover the voids of the mixture so that the infiltration rate decrease. The effect of superplasticizer with a concentration more than 1% can increase the strength significantly as happened in third variation because the high superplasticizer content can increase workability so that the mixture compact easily. However, if the superplaticizer concentration is used too high, segregation will occur in the mixture.