Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Developing non-heat treated UHPC in South Africa
Thesis (PhD)--Stellenbosch University, 2015.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2015
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613970726125568 |
|---|---|
| access_status_str | Open Access |
| author | Zang, Jin |
| author2 | Van Zijl, G. P. A. G. |
| author_browse | Van Zijl, G. P. A. G. Zang, Jin |
| author_facet | Van Zijl, G. P. A. G. Zang, Jin |
| author_sort | Zang, Jin |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2015. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/96699 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:36.436Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/96699 Developing non-heat treated UHPC in South Africa Zang, Jin Van Zijl, G. P. A. G. Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. UHPC -- Non-heat treated Ultra-high Performance Concrete (UHPC) -- South Africa UCTD Thesis (PhD)--Stellenbosch University, 2015. ENGLISH ASTRACT: The very high strength, enhanced ductility and long-term durability of ultra-high performance concrete (UHPC) makes it an ideal material to be used for building structures in the future. The non-heat treated UHPC requires less quality control than heat treated UHPC, which makes it more relevant to be applied in South Africa. This research focuses on developing non-heat treated UHPC with locally available materials, with the exception of short, straight, high strength steel fibre. While UHPC mix design guidelines have been proposed, ingredient materials available locally, but which do not necessarily comply with recommended property ranges, may be compensated for by particular strategies. The local ingredient materials are compared based on their mineralogy, specific surface area, particle size and grading by researchers who successful developed non-heat treat UHPC. The majority of local materials were found not that ideal for UHPC. Under such circumstances, following the general UHPC mix design, it is difficult to reach the same designated strength as those achieved by the other researchers. One of the problems for non-heat treated UHPC is its large shrinkage caused by very low water to cement ratio. A new mix design philosophy is developed for UHPC by making use of steel fibre to improve its compressive strength. Instead of avoiding the large shrinkage, this method uses shrinkage to improve the bond between steel fibre and matrix through the mechanism of shrinkage induced clamping pressure. Subsequently, the mechanism of bridging effect of steel fibre is used to confine shrinkage evolvement in UHPC. Through such a mix design philosophy, the steel fibres are pre-stressed inside UHPC so that it both improves the compressive strength and ductility. A UHPC strength of 168 MPa is achieve in this research. After the UHPC has successfully been developed, factors that can affect UHPC strength are tested. It is found that the environmental temperature of UHPC, cement composition and specimen cover during the moulded period significantly influence UHPC strength by approximately 24%. It is also found that after two days of de-moulding, the UHPC exposed to the air, achieved similar strength as that cured in water, which is helpful for future industrial application. Doctoral 2015-05-20T09:13:54Z 2015-05-20T09:13:54Z 2015-03 Thesis http://hdl.handle.net/10019.1/96699 en_ZA Stellenbosch University xvii, 157 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | UHPC -- Non-heat treated Ultra-high Performance Concrete (UHPC) -- South Africa UCTD Zang, Jin Developing non-heat treated UHPC in South Africa |
| title | Developing non-heat treated UHPC in South Africa |
| title_full | Developing non-heat treated UHPC in South Africa |
| title_fullStr | Developing non-heat treated UHPC in South Africa |
| title_full_unstemmed | Developing non-heat treated UHPC in South Africa |
| title_short | Developing non-heat treated UHPC in South Africa |
| title_sort | developing non heat treated uhpc in south africa |
| topic | UHPC -- Non-heat treated Ultra-high Performance Concrete (UHPC) -- South Africa UCTD |
| url | http://hdl.handle.net/10019.1/96699 |
| work_keys_str_mv | AT zangjin developingnonheattreateduhpcinsouthafrica |