| Project/Area Number |
15560698
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Earth system and resources enginnering
|
|---|
| Research Institution | MURORAN INSTITUTE OF TECHNOLOGY |
|---|
Principal Investigator |
KODAMA Jun-ichi Muroran Institute of Technology, Department of engineering, Associate Professor, 工学部, 助教授 (70241411)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
|---|
| Keywords | Freezing and thawing test / Lapping method / Standard method / Deterioration rate / Crack / Durability / Rock / Weight loss / 膨張ひずみ / 溶結凝灰岩 / 弾性波速度 / 片岩 / 含水状態 |
|---|
| Research Abstract |
A new testing method referred to "lapping method" was developed in order to evaluate quickly durability of rocks subjected to freezing and thawing cycles. Then, the relationship between the durability of rocks subjected to freezing and thawing cycles and some physical properties was investigated. Main results are summarized as follows.
Freezing and thawing tests were conducted on rocks with the lapping method and a standard method suggested by ASTM. Deterioration rate of rocks was examined in these two methods. Consequently, crack initiation in the lapping method was faster than that in the standard method. It is cleared that the deterioration rate in the lapping method is faster than that in the standard method in the early stage. However, crack propagation rate and number of cycles to breaking was faster in the standard method than in the lapping method. Water content of the specimen gradually increased during test in the standard method, but it is almost constant in the lapping method. This fact may attribute to crack propagation and breaking.
Freezing and thawing tests were carried out with nine kinds of rocks to study a relationship between weight loss at 60th cycles and coefficient of water absorption or tensile strength. The weight loss shows an increase with an increase in the coefficient of water absorption and with a decrease in tensile strength. It was found that the weight loss is positively correlated with the coefficient of water absorption, and negatively correlated with the tensile strength. No Crack initiation can be observed in rock specimens when its tensile strength is higher than 2 MPa. These results indicate that durability of rocks subjected to freezing and thawing cycles can be estimated with their coefficient of water absorption or their tensile strength
|
