Indian Journal of Engineering & Materials Sciences Vol. 24, December 2017, pp. 507-515 Influence of mineral additives on the properties of pervious concrete Yuwadee Zaetang a , Ampol Wongsa b , Vanchai Sata b & Prinya Chindaprasirt b * a Department of Civil and Environmental Engineering, Kasetsart University Chalermphrakiat, Sakon Nakhon Province Campus, Sakon Nakhon 47000, Thailand b Sustainable Infrastructure Research and Development Center, Department of Civil Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen 40002, Thailand Received 6 January 2015; accepted 7 April 2017 Pervious concrete is a permeable concrete which presents a lower strength than conventional concrete due to its high porosity. The strength of pervious concrete can be improved by using a low w/c paste with additives or admixtures. This study focused on the addition of mineral additives (diatomite, fly ash, limestone dust, and fine sand) in a low water to cement ratio (w/c) paste to improve the strength and other properties of pervious concrete. The strength, total void content, density, thermal conductivity, and abrasion resistance of pervious concrete were investigated. The results show that these additives increase the paste volume and improve the mechanical properties of pervious concrete. The improvement from addition of diatomite or fly ash is due to both chemical and filler effects, while that from addition of inert limestone dust or fine sand is only due to filler effect. Pervious concrete with mineral additives show increase in strength and abrasion resistance with a slight increase in density and thermal conductivity. The incorporation of 10% fine sand is highly desirable in this study as it gives high strength and high permeability. The high permeability is probably due to the use of large particle sand with little or no fine particles which led to an improved continuous void. Keywords: Pervious concrete, Additive, Diatomite, Fly ash, Limestone dust, Fine sand Adding inert filler and pozzolan to blended cements has been widely investigated. In general, the addition of inert material produces a filler effect and the addition of pozzolan produces both filler effect and chemical effect 1-3 . As a result of the use of fine inert material, the filler effect allows dense packing within the matrix and generates a large amount of nucleation sites for the precipitation of hydration products 4-6 . Limestone and fine sand as inert fillers, therefore, produce mainly the filler effect in cement paste. For pozzolan, active silica and alumina react with calcium hydroxide and produce additional calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH). This mechanism makes the paste homogeneous and dense 7,8 . Diatomite and fly ash are fine powder materials with active silica and alumina and thus can be used as pozzolanic additives 9 . Pervious concrete (PC) has been defined as an environmentally friendly material 10,11 . Connected voids are deliberately incorporated into this concrete, allowing air and water to pass through and improve the acoustic and thermal insulation properties of this concrete 12,13 . PC has been widely used in various construction applications with emphasis on the environment 14-17 . However, as the mechanical strengths of PC are inferior to those of conventional concrete due to the voids, this type of concrete is used when a high load is not the prime requirement such as parking lots, sidewalks, bicycle paths, and park pathways. ACI 522R-10 report 10 provides information that the compressive strengths of PC typically range from 2.8-28.0 MPa, are often less than 14.0 MPa when used in shoulder pavement applications, and around 7.0 MPa when used in permeable base applications. There are a number of studies and reports on the basic properties and improvements of the mechanical properties of pervious concrete. Chindaprasirt et al. 18 confirmed that an increase in void content or a decrease in binder strength reduced the compressive strength of PC. The use of silica fume and superplasticizer (SP) enhanced the mechanical and physical properties of PC 19,20 . For making PC with low w/c paste (0.20–0.25), superplasticizer is usually incorporated to maintain workability. The use of sufficiently high workability in cement paste results in the continuity of cement paste with embedded coarse aggregate such that continuous void is maintained 21 . However, for low w/c concrete, —————— *Corresponding author (E-mail: prinya@kku.ac.th)