Author: Kyong-Ku Yun, Professor and Director—Center for Regional Construction Technology, Dept. of Civil Engineering, Kangwon National University 1 Kangdae-gil, Chuncheon, 200-701, S. Korea; Corresponding Author: Kyong Namkung, kkyun@kangwon.ac.kr, Doctoral Student—Dept. of Civil Eng. Kangwon National University, 1 Kangdae-gil, Chuncheon, 200-701, S. Korea; and Sung-Il Jeon, Seniorost Researcher—Highway Pavement Research Division, Korea Institute of Construction Technology, 283 Goyangdae-Ro, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 411-712, Korea.
ABSTRACT:
Two-lift concrete paving (2LCP) involves placing two layers of concrete “wet-on-wet” instead of the traditional method of using a single homogeneous layer of concrete. The thick bottom layer offers the opportunity to optimize the use of local aggregates; recycled materials to produce an economical, durable, and sustainable pavement system with the most desirable surface characteristics—like improved skid resistance and reduced noise provided by the high-quality surface of the high-performance concrete. The time between placing layers is often no more than 30 minutes. Perhaps the challenge involved in the construction of two-layer concrete systems includes the additional costs and logistics required for two plants to produce different concrete mixtures, and two slip-form pavers for paving both of bottom and top layers.
A very simple and economic method for remixing an ordinary Portland cement concrete (OPC) into a high performance concrete (HPC) at a job site was developed, which is called “Cellular-sprayed concrete”. Cellular-sprayed concrete is produced by incorporating a preformed foam and fine powders in a ready mixed concrete , and is conveyed under pressure through a pneumatic hose or pipe, and projected into place at high velocity with simultaneous compaction. This method can solve the problem of two-batch plants and two pavers in 2LCP construction.
“Cellular sprayed concrete” was developed which enable remixing OPC into HPC at a job site, and which enable utilizing a single batch plant and single slip-form paver for constructing 2-lift concrete pavement—instead of 2 batch plants and 2 pavers, respectively. This results in a very simple, economic and innovative way for 2LCP.
For more information, please contact: Kyong-Ku Yun | E-mail: kkyun@kangwon.ac.kr
Home page PHOTO: “Typical 2LCP Construction” from the Paper/Abstract: “Feasibility Study of Two-Lift Concrete Paving: Technical Report”;
April 2014; Author(s): Jiong Hu, David Fowler, Md Sarwar Siddiqui, and David Whitney;
Texas State University-San Marcos The Texas State University System San Marcos, Texas 78666-4684;
and Center for Transportation Research The University of Texas at Austin 3208 Red River, Suite 200 Austin, TX 78705-2650.