Influence of the use of Hualien Industrial Wastes (fine granite chips, clam shell) on the Physical Property and of Alkali-Activated Slag Concrete

• Main Authors: Yao-Hsin Chi, 紀堯馨
• Other Authors: Yen-Pei Fu
• Format: Others
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/14100180783771824983

碩士 === 國立東華大學 === 材料科學與工程學系 === 101 === This study represents an investigation into physical and mechanical properties(degree of hydration, porosity and compressive strength) and electrical resistivity of alkali-activated slag concrete (AASC) produced from granulated blast furnace slag(GBFS) with industrial wastes (fine granite chips and clam shell ). Sodium hydroxide solution and liquid sodium silicate with 0.33 of modulus ratio (mass ratio of Na2O to SiO2 ) were used as alkaline activators to activate GBFS, and the dosage of industrial wastes was 0%, 1%, 5%, 10% and 20% . All those properties and electrical resistivity of AASC mentioned above were tested and compared with each other to understand the influence of alkaline activators and industrial wastes toward the slag concrete. As a result, the AASC samples activated by 5M of sodium hydroxide showed poor mechanical performance (38.82 MPa for 14 days of curing) with strength losses(15-20%) occurred in the long curing term (more than 28 days). For sodium silicate,AASC samples with 0.3 of mass ratio of sodium silicate to GBFS possess high strengths (58.17 MPa or 28 days of curing) and stability. The AASC specimens with 1% fine granite chips and 1-20% clam shell were found to have higher compressive strength than ordinary portland cement, and sample with 1% of clam shell addition has the highest strength. The degree of hydration of concrete is related to chemically bonded water which was calculated from the weight change between 105℃ and 1000℃ of thermal treatment. According to the result, it was observed that both compressive strength and the degree of hydration are related to the dosage of alkaline activator. On the other hand, the addition of granite chips in GBFS causes a reduction in hydration, but it has no effect on the clam shell added sample. The electrical resistivity of the concrete pastes at different dosage of alkaline activators and industrial wastes were determined using Wenner's method. The electrical resistivity was slightly decreased after mixing, and then increased obviously. When sample possesses higher contents of activator and industrial wastes, the phenomenon of increasing of electrical resistivity occurred later and the value of electrical resistivity was lower. Since clam shell wastes are available in vast amounts in Hualien, resource recycling of these materials in the production of more durable concrete is economical and sustainable to the environment.