Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints
This study carried out a comparison between cement grouting and chemical grouting, using epoxy and polyurethane, with respect to their effects on the shear behavior of joints. Joint replicas, with three different grades of surface roughness, were molded and grouted by means of cement and epoxy grout...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-03-01
|
| Series: | Polymers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4360/14/6/1229 |
| _version_ | 1797443139194060800 |
|---|---|
| author | Milad Abolfazli Milad Bazli Hossein Heydari Ahmad Fahimifar |
| author_facet | Milad Abolfazli Milad Bazli Hossein Heydari Ahmad Fahimifar |
| author_sort | Milad Abolfazli |
| collection | DOAJ |
| description | This study carried out a comparison between cement grouting and chemical grouting, using epoxy and polyurethane, with respect to their effects on the shear behavior of joints. Joint replicas, with three different grades of surface roughness, were molded and grouted by means of cement and epoxy grouts of various mixtures. To investigate their shear behavior, samples were subjected to direct shear tests under constant normal load (CNL) condition. According to the results obtained, grouting improves the overall shear strength of the rock joints. All the grouted samples yielded higher maximum and residual shear strength in comparison with the non-grouted joint. Grouting resulted in an improvement in the cohesion of all the samples. However, a fall in friction angle by 5.26° in the sample with JRC of nine was observed, yet it was reduced by 2.36° and 3.26° for joints with JRC of 14 and 19, respectively. Cement grouts were found to have a more brittle behavior, whereas the chemical grouts were more ductile. Higher amounts of cement used in the grout mixture do not provide as much cohesion and only increase the brittleness of the grout. As a result of being more brittle, cement grout breaks into small pieces and joint planes are in better contact during shearing; consequently, there would be less of a fall in friction angle as opposed to epoxy grout whose ductile characteristic prevents grout chipping; therefore, joint planes are not in contact and a greater fall in the friction angle occurs. There was no noticeable change in the cohesion of the larger grouted joints. However, the friction angle of both natural and grouted joints increased in the larger joint. This can be related to the distribution of random peaks and valleys on the joint surface, which increases with the joint size. |
| first_indexed | 2024-03-09T12:51:44Z |
| format | Article |
| id | doaj.art-34e16fcfba804bb8b974d63ae8738a6b |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T12:51:44Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-34e16fcfba804bb8b974d63ae8738a6b2023-11-30T22:04:22ZengMDPI AGPolymers2073-43602022-03-01146122910.3390/polym14061229Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock JointsMilad Abolfazli0Milad Bazli1Hossein Heydari2Ahmad Fahimifar3College of Engineering, IT and Environment, Charles Darwin University, Darwin 0815, AustraliaCollege of Engineering, IT and Environment, Charles Darwin University, Darwin 0815, AustraliaDepartment of Engineering, Kharazmi University, Karaj 15719-14911, IranDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran 15875-4413, IranThis study carried out a comparison between cement grouting and chemical grouting, using epoxy and polyurethane, with respect to their effects on the shear behavior of joints. Joint replicas, with three different grades of surface roughness, were molded and grouted by means of cement and epoxy grouts of various mixtures. To investigate their shear behavior, samples were subjected to direct shear tests under constant normal load (CNL) condition. According to the results obtained, grouting improves the overall shear strength of the rock joints. All the grouted samples yielded higher maximum and residual shear strength in comparison with the non-grouted joint. Grouting resulted in an improvement in the cohesion of all the samples. However, a fall in friction angle by 5.26° in the sample with JRC of nine was observed, yet it was reduced by 2.36° and 3.26° for joints with JRC of 14 and 19, respectively. Cement grouts were found to have a more brittle behavior, whereas the chemical grouts were more ductile. Higher amounts of cement used in the grout mixture do not provide as much cohesion and only increase the brittleness of the grout. As a result of being more brittle, cement grout breaks into small pieces and joint planes are in better contact during shearing; consequently, there would be less of a fall in friction angle as opposed to epoxy grout whose ductile characteristic prevents grout chipping; therefore, joint planes are not in contact and a greater fall in the friction angle occurs. There was no noticeable change in the cohesion of the larger grouted joints. However, the friction angle of both natural and grouted joints increased in the larger joint. This can be related to the distribution of random peaks and valleys on the joint surface, which increases with the joint size.https://www.mdpi.com/2073-4360/14/6/1229rock jointcement groutingchemical groutingshear behavior |
| spellingShingle | Milad Abolfazli Milad Bazli Hossein Heydari Ahmad Fahimifar Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints Polymers rock joint cement grouting chemical grouting shear behavior |
| title | Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints |
| title_full | Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints |
| title_fullStr | Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints |
| title_full_unstemmed | Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints |
| title_short | Investigating the Effects of Cement and Polymer Grouting on the Shear Behavior of Rock Joints |
| title_sort | investigating the effects of cement and polymer grouting on the shear behavior of rock joints |
| topic | rock joint cement grouting chemical grouting shear behavior |
| url | https://www.mdpi.com/2073-4360/14/6/1229 |
| work_keys_str_mv | AT miladabolfazli investigatingtheeffectsofcementandpolymergroutingontheshearbehaviorofrockjoints AT miladbazli investigatingtheeffectsofcementandpolymergroutingontheshearbehaviorofrockjoints AT hosseinheydari investigatingtheeffectsofcementandpolymergroutingontheshearbehaviorofrockjoints AT ahmadfahimifar investigatingtheeffectsofcementandpolymergroutingontheshearbehaviorofrockjoints |