The Paper of 2 nd Abstract for EACEF 2011 – Yogyakarta, Indonesia, 20-22 September 2010. 1. Self-compacting Concrete in Its Durability Performance (BM017) Chao-Lung Hwang 1,a , Fransiscus Mintar Ferry Sihotang 2,b , Chun-Tsun Chen 1,c , Bui Le Anh Tuan 3,d 1 Department of Construction Engineering, National Taiwan University of Science and Technology, Taipei 10672, Taiwan, ROC. 2 Department of Civil Engineering, University of Pelita Harapan, 15811, Indonesia. 3 Department of Civil Engineering, Can Tho University, Vietnam. a cmrl@seed.net.tw, b fmintarfs@yahoo.com, c D9505402@mail.ntust.edu.tw, d blatuanlx@yahoo.com, ABSTRACT Self-compacting concrete (SCC) which can be compacted into every corner of a formwork, purely by means of its own weight and without the need for vibrating compaction. The method for achieving self- compacting involves not only high deformability of paste or mortar, but also resistance to segregation between coarse aggregate and mortar when the concrete flows through the confined zone of reinforcing bars. Many concrete structure projects have been done in Taiwan using SCC by DMDA method, one of them is Nanggang project. DMDA method can create high density and high design strength with low water and cement content to achieve the high cement strength efficiency. With the water-to-cement ratio is higher than 0.42, water content is less than 160 kg/m 3 and cement content is less than f’c/20, the stability of SCC’s volume can be controlled then the high physical density, high flowability and high homogeneity can be achieved. In 14 days after SCC making, the designed strength of 350 kgf/cm 2 had been exceeded. High durability of SCC had been achieved in 365 days after making, with 4305 meter/seconds in ultrasonic test and 210 kΩ.cm in electrical resistivity. Keywords: self-compacting concrete, durability. 1. Introduction. Self-compacting concrete (SCC), a new kind of high performance concrete (HPC) with excellent deformability and segregation resistance, was first developed in Japan in 1986. It is a special kind concrete that can flow through and fill the gaps of reinforcement and corner of molds without any need for vibration and compacting during the placing process [1,2]. SCC has some favorable characteristic, such as high fluidity, good segregation resistance and the distinctive self-compacting ability without any need for vibration during the placing process [3]. In 1993, Okamura proposed a mix-design method for SCC [1]. His main idea was to conduct first the test on paste and mortar in order to examine the properties and compatibility of superplasticizer (SP), cement, fine aggregate and supplementary pozzolanic materials, and then followed by trial mix of SCC. The major advantage of this method is that it avoids having to repeat the same kind of quality control test on concrete, which consumes both time and labor. The drawbacks of Okumura’s method, there are two things to note: firstly, it requires quality control of paste and mortar prior to SCC mixing, while many ready-mixed concrete producers do not have the necessary facilities for conducting such test and the second, the mix-design method and producers are too complicated for practical implementation. In recent years many researchers have established SCC by using supplementary cementitous materials, like: fly ash, blast furnace slag, silica fume etc. The supplementary cementitous materials can improve the various properties in fresh and hardened states concrete. SCC in general contains a large amount of powder materials, a superplaticizer and/or viscosity modifying admixtures. The high powder content is often supplemented by mineral admixtures that could increase the slump of concrete mixture without increasing its cost. The use of fly ash also reduces the demand for cement, fine fillers and sand which are required in SCC [4]. For site quality control, two test methods are generally sufficient to monitor production quality of SCC. Typical combinations are slump flow and V-funnel or slump flow and J-ring. However, filling and passing ability cannot be evaluated sufficiently by slump-flow test alone [5]. 2. Durability. From rheological point of view, a successful SCC is characterized by low yield stress necessary for high capacity of deformation and moderate viscosity to ensure uniform suspension of solid particles during casting. Reducing the water content and increasing the concentration of fine particles can enhance the cohesion and viscosity, and hence the stability of SCC. Free water is the total water minus water that is