Issue 22

A. Namdar, Frattura ed Integrità Strutturale, 22 (2012) 26-30 ; DOI: 10.3221/IGF-ESIS.22.04 26 Natural minerals mixture for enhancing concrete compressive strength Abdoullah Namdar Faculty of Civil Engineering & Earth Resources, Universiti Malaysia Pahang, Malaysia ab_namdar@yahoo.com A BSTRACT . The construction material quality is required to be improved in order to enhancing structure stability, optimizing construction cost and quality. The kaolin and bentonite have been mixed in equal quantity and treated by heat for 1 hour under 600 ºC, 800 ºC and 1000 ºC to create new minerals under high temperature condition to introduce an acceptable concrete additive for achieving concrete compressive strength in early age. To study micro properties of additive-cement mixture, X-ray and FESEM experiments have been used. The results indicate that acceptable proportion of unheated kaolin-bentonite is improving the concrete compressive response. But if kaolin-bentonite mixture treated by heat under 800 ºC and in quantity of 12 % has been used in concrete mixed design, then the concrete compressive strength of 7 days shows the best result. The result is due to the development of new minerals under high temperature condition in mineral mixture and also kaolin- bentonite additive change cement past crystal and lead to enhancement of nano structural cement bonding. K EYWORDS . Concrete additive; Kaolin; Bentonite; Heat treatment; New minerals. I NTRODUCTION he use of high-fast strength concrete has many applications, both technical and economical. Over last decade, the high strength concrete in short time was very important issue for researcher. The reconnaissance on economically and feasibility concrete additive is highly significant in construction industry. A high strength concrete is introduced by using large volumes of low calcium as an additive and compressive strength of 80 MPa was for 28 days [1]. The various chemical and supplementary cementitious materials are investigated on improvement concrete compressive strength [2-3]. And also fly ash, bottom ash and coarse aggregate mechanical properties and quality are evaluated for enhancement of concrete compressive strength [4-7]. The natural minerals are shown good results among other techniques. The investigation show natural minerals are improved concrete compressive strength and cement geopolymer [8-11]. From other view of point the investigation on materials macroscopic quality and minerals in concrete mix design is important topic for construction industry [12-13]. For example geopolymers can be synthesized from aluminosilicate powders including natural pozzolans [14-15]. The replacing cement by mineral additions resulted in lower early age strength and low cement quantity consumption [16]. The modern construction projects are trust to high strength concrete [17]. To optimize admixture cost and better improvement concrete characteristics many methods have been introduced [18-20]. The natural minerals mixture treatment by heat to develop new minerals based on kaolin-benonite interaction minerals in high temperature for produced new materials which can be useful as a concrete additive in concrete mixed design process have been investigated in order to improve concrete compressive strength in short term for minimizing construction time and cost. T