| Title |
Compressive Strength and Elastic Modulus Properties of High-Performance Rammed Earth Concrete |
| Authors |
Yang Keun-Hyeok ; Hwang Hey-Zoo |
| Keywords |
Rammed Earth Concrete ; Hwangtoh ; Compressive Strength ; Placing Position ; Elastic Modulus |
| Abstract |
This study examined the effect of specimen size on the compressive strength and elastic modulus of high-performance rammed earth concrete. Natural hwangtoh or alkali-activated (AA) hwangtoh was used for cementless binder. The diameter of cylindrical specimens varied from 100 mm to 300 mm, while the aspect ratio of specimens remained constant to be 2.0. In addition, a rammed earth wall of 2400×1800×300 mm was constructed and cylindrical core samples of 100×200 mm were prepared from the wall in order to evaluate the compressive strength of rammed earth concrete against the placing position of the concrete. Test results showed that the decreasing rate of compressive strength according to the increase of specimen size was more prominent in rammed concrete than in wet-cast concrete. In particular, the scale factor for cylindrical specimen with 100 mm diameter against that with 150 mm diameter was recorded to be 0.52 and 0.6 for natural hwangtoh-based rammed concrete and AA hwangtoh-based rammed concrete, respectively, indicating that these values are much lower than the scale factor for ordinary portland cement concrete specified in ACI 318-08 code provision. The compressive strength of rammed earth concrete was also significantly affected by the placing position of concrete. The compressive strength measured from core specimens sampled from bottom zone of rammed earth concrete wall was lower by around 35% than that measured from top zone. On the other hand, the elastic modulus of AA hwangtoh-based rammed concrete could be conservatively predicted using the equation proposed by ACI 318-08 when the diameter of cylindrical specimen was below 200 mm. |