| Summary: | 碩士 === 淡江大學 === 土木工程學系 === 92 === Reuse of steel furnace slag in pavement engineering has been years in many countries. Steel slag is hard, high density, durable and good particle shape and, therefore, is applied as aggregate in roadbed, subbase, base and shoulder as well as in asphalt surfacing.
This study was to evaluate the reuse of electric arc furnace (EAF) oxidizing slag for substitution of aggregate in asphalt concrete. There were three stages in laboratory work of this study. First, examined the basic properties of asphalt cement, natural aggregate and EAF slag. Second, determined the optimum asphalt contents by Marshall mix design method. Third, evaluated the performance of asphalt concrete specimens containing EAF slag. Major findings based on the results of this laboratory study were summarized as follows:
1. Laboratory results showed that EAF slag could improve aggregate interlock due to its little flat particles, high fractured faces and angular shapes. EAF slag had low silt content, low abrasion and good soundness, and met the limits of expansion as specified in CNS 14602.
2. The difference of specific gravity between EAF slag and natural aggregate is larger than 0.2. Caution was exercised in altering the proportioning weighs to maintain the volumetric relationships. The Marshall mix design results showed that the higher the substitute percentage was the higher the optimum asphalt contents based on volume would be.
3. The laboratory performance test results showed that EAF slag groups improved resilient modulus, indirect strength, skid resistance, and rutting resistance of asphalt concrete. Results also showed that laboratory aging had little effect on EAF slag groups. Stripping test results showed that the stripping potential of EAF slag groups are less than the control group.
4. Based on the results of this laboratory study it was found that the use of EAF slag in asphalt concrete looked feasible. Although the binder costs increase due to higher optimum asphalt contents of EAF slag groups, it may be offset by the cheaper price of EAF slag. Thus, reduce the total cost of asphalt concrete containing EAF slag.
|
|---|
