Evaluation of high-performance porous concrete properties M. Aamer Rafique Bhutta a , K. Tsuruta b , J. Mirza c,⇑ a Faculty of Civil Engineering, University Teknologi Malaysia, Malaysia b Materras Oume Concrete Industry, Ltd., Japan c Department of Robotics and Civil, Research Institute of Hydro-Québec, Varennes, Québec, Canada J3X 1S1 article info Article history: Received 4 July 2011 Received in revised form 1 December 2011 Accepted 4 December 2011 Available online 20 January 2012 Keywords: High performance porous concrete Self-compaction Permeability Compressive strength Flexural strength Strength development rate Total void ratio abstract The aim of this laboratory study was to evaluate the properties of high performance porous concrete. It required no special vibration equipment and curing. The optimum mixture proportions were used in the preparation of high performance porous concretes containing three sizes of coarse aggregates with appropriate amount of high water-reducing and thickening (cohesive) agents. Tests carried out on this concrete were: slump, slump-flow, void ratio, and coefficient of permeability, compressive and flexural strengths, and strength development rate. Furthermore, a test was proposed to determine the effects of high water-reducing and thickening (cohesive) agents on self-compaction of high performance porous concrete. It was meant to evaluate its hardened properties from the viewpoint of practical application. Its strength development rate was also examined at curing age of 1, 3, 7, 14 and 28 days at 20 °C and 60% relative humidity (R. H.). Consequently, high performance porous concrete exhibited good workability and cohesiveness with no segregation or bleeding, and developed high strength compared to conven- tional porous concrete. The results of proposed self-compaction test for this porous concrete also showed good workability and cohesiveness without any special compaction or vibration. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Porous concrete was developed as an environmentally friendly material in Japan in the 1980s. Since then it has been widely used in various applications in Japan, USA and Europe because of its multiple environmental benefits: controlling storm water runoff, restoring groundwater supplies, and reducing water and soil pollu- tion [1–6]. Due to the water-permeating, water-draining, and water retaining performances of the porous concrete, it has been utilized in road pavements, sidewalks, parks, and building exteri- ors. This concrete has also been used for plant bedding and perme- able rainwater retention facilities, such as permeable trenches, permeable gullies and permeable gutters [7–9]. In general, a gap- graded conventional porous concrete (CPC or ‘‘no fines’’ concrete, i.e., where the fine aggregate is omitted entirely) is obtained by using a uniform size of coarse aggregate at low water–cement ratio (W/C). However, this CPC showed poor workability (<30%), needed vibration equipment for proper compaction and curing for the pro- duction of precast products, and for drainage pavement application [10]. This research study tried to develop and evaluate the properties of high performance porous concrete (HPPC) in the laboratory. The purpose was to examine the applicability of HPPC in terms of its practical application in place of CPC. A test was also developed to determine the effect of the thickening (cohesive) and high water- reducing agents (SP) on self-compaction of HPPC on its hardened properties from the viewpoint of practical application. As a result, this newly developed porous concrete exhibited good workability and cohesiveness with no segregation or bleeding and provided high strength compared to CPC. 2. Experimental 2.1. Materials Ordinary Portland cement and three different sizes of crushed coarse aggregates No. 5 (13–20 mm); No. 6 (5–13 mm) and No. 7 (2.5–5 mm) were used to prepare all porous concretes. A commercially available SP (density: 1.06 g/cm 3 ), and a thicken- ing (cohesive) agent (water-soluble cellulose based polymer powder, density: 2.40 g/cm 3 ) were employed for the preparation of porous concretes. SP was added to make low water–cement binder more workable in order to achieve the desired workability whereas the thickening agent helped in preparing cement paste more viscous and without bleeding or segregation. The amounts of these admixtures were calculated based on OPC weight. 2.2. Specimens preparation Tables 1 and 2 show the specimen composition of CPC and HPPC, respectively. They were prepared according to JIS Method of Making Porous Concrete Specimens (draft) at ambient laboratory temperature of 20 ± 1 °C and placed at 100% R. H. for 1-day. After de-molding, all specimens were placed at 20 ± 1 °C and 60% R. H. for 27 days. HPPC contained SP and thickening agent. It is well known that for an opti- mum film formation, a dry cure is required. On the other hand, cement hydration 0950-0618/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.conbuildmat.2011.12.024 ⇑ Corresponding author. Tel.: +1 450 652 8308. E-mail address: mirza@ireq.ca (J. Mirza). Construction and Building Materials 31 (2012) 67–73 Contents lists available at SciVerse ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat