Stainless slag is by-product on the production of stainless steel. In Japan, stainless slag is generated approximately 30,000 ton every year. The authors investigated basic physical properties of concrete used stainless slag as fine aggregate and derived that stainless slag can be used as fine aggregate of concrete up to 60% in mix proportion without any caution. This study aims at using stainless slag effectively as a material of structural concrete. In order to promote stainless slag as fine aggregate on the structural purpose, Behavior and performance of RC simple beams used stainless slag were investigated experimentally. In the experiment of loading test, perform of ...view middle of the document...
5 ± 1.5. AE water reducing agent (Frolich SV) in admixture is 0.1 % total amount of cement.
Table 1. Description concrete material
Material Density (g/cm3) Water absorption (%) FM
Sea Sand (S) 2.57 1.62 2.85
Crushed Gravel (G) 2.70 1.00 20
Ordinary Cement (C) 3.15 -
Stainless Slag 3.08 1.53 2.95
Water (W) 1.00
Table 3. Mix proportion of concrete
W/C Material (kg/m3) Slump Design (cm) Slump Measured (cm) Air content Design (%) Air content Measured (%)
Slag 0 % 28 days 50 170 340 0 696 1097 3.40 12±2 12 4.5±1.5 3.5
Slag 60 % 28 days 50 170 340 500 278 1097 3.40 10.5 3.8
Slag 0 % 91 days 50 170 340 0 696 1097 3.40 10 3.5
Slag 60 % 91 days 50 170 340 500 278 1097 3.40 10 3.5
Figure 1. dimension and loading of RC beam
2.2 Concrete specimens
The cylindrical specimens were prepared for the compressive strength, split testing (tensile strength) and elastic modulus test. The specimens were cured in the water pool, with temperature and moisture control until the testing day. The testing methods are based on Japanese industrial standard (JIS), namely JIS A 1108 for compressive strength test, JIS A 1113 for Split tensile testing and JIS A 1149 for elastic modulus at the age 28 and 91 days.
2.3 Reinforced Concrete (RC) beams
Two types are used stirrups and without using a stirrup of beams shown in Figure 1 designed, fabricated and loaded up to failure condition. To investigate the structural behavior of beams using stirrups and without stirrup, two specimens corresponded to each stainless slag composition were prepared. RC beams with a similarity of dimension (200mmx150mm), effective depth (160mm), and reinforcement ratio (0.016) were fabricated. Then, after casting, pouring with water, placing and covering outside building, thus temperature depended on the weather condition. The method used to cure RC beams was by the sealed and spray with water every day until the loading age of 28 days and 91 days. The measurement and loading position of RC beams specimen are shown in Fig. 1, correspondingly. The strain gauge attached to the main reinforcement in center of beam and other strain gauge attached at center between loading point and support point. The crack location, crack width, and crack length were measured after cracks appeared. Crack widths were measured at every load interval at the tension steel level and the crack formations were marked on the beam.
3. Result and Discussion
3.1 The property of concrete specimens
Table 4 shows compressive strength, tensile strength and elastic modulus at 28 and 91 days. The compressive and tensile strength of concrete containing stainless slag were slightly higher than those without using stainless slag, including development of mechanical property of concrete during curing showing the condition of compressive strength and tensile strength concrete increasing. However, the elastic modulus of concrete no shows significant...