03780425215903030525315010300392949166919391030030423019391930024066301919154915651070965120900870107087015153.1 Preparation of the specimen─ 4 ─Fig. 6 Relationship between water-cement ratio and compressive load as compared with the control specimen of W/C 60%Fig. 7 Reinforcing bar arrangementhemispherical head loading, the single-point flat head loading, and the single-point hemispherical head loading normalized with the flat head loading applied to the 150×150×150mm cubic specimen and φ100×200mm cylindrical specimen. In the case of 150×150×150mm cubic specimens, the four-point hemispherical head loading did not show much difference by the W/C, and it always broke at a load of 10 to 15% of the flat head loading. In the case of φ100×200mm cylindrical specimens, the compressive fracture load ratio decreased as the W/C decreased both in the single-point hemisphere loading and the single-point flat loading.(3) Normalization by the specimen with a W/C of 60%Fig. 6 shows normalized compressive load of specimens subjected to the loading with four-point hemispherical head, single-point flat head and single-point hemispherical head with respect to the specimen with a W/C of 60%.In the case of 150×150×150mm cubic specimen with a W/C less than 20% as shown left in Fig.6, compressive strength obtained with a four-point hemisphere head loading was 2.5 to 4.5 times as much as that with W/C of 60%, while fracture load was about twice.In the case of φ100×200mm cylindrical specimen with a W/C less than 20% as shown right in Fig.6, compressive strength obtained with the single-point flat head loading and the single-point hemispherical head loading are 3.5〜7.0 times as much as with the W/C of 60%, while fracture load was 2.3 to 3.7 times.The specimen was an mock-up beam member (300×300×900mm). A steel mold was used and 8 main bars (D19) and 20 stirrup (D10) were used as the reinforcing bars. The bar arrangement is shown in Fig. 7.The W/C of the concrete were 60%, 20%, 16% and 13% and the mix proportions are shown in Table 2. Materials used are 3. Crushing experiment using mock-up beam specimens
元のページ ../index.html#6