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Impact of environmental exposure on concrete strength in highway bridges in Uganda

Bakamwesiga, Hilary; Mwakali, Jackson; Sengendo, Stephen and Thelandersson, Sven LU (2014) 1st International Conference on Construction Materials and Structures In Proceedings of the First International Conference on Construction Materials and Structures p.861-870
Abstract
Deterioration of concrete structures is a worldwide problem. Environmental exposure is known to affect concrete strength in structures. While moisture affects rebound values by lowering them, carbonation does the opposite. The aim of the study was to determine the in-situ concrete strength of three bridge elements, namely, pier, abutment and deck and evaluate the environmental conditions such as moisture and abrasive forces on the near surface of concrete. Acknowledging that destructive tests on concrete are expensive and time consuming, this research used rebound hammer test -a non-destructive test (NDT) method. The easiness, simplicity and portability of the rebound hammer made it possible to cover all 13 highway bridges in a period of... (More)
Deterioration of concrete structures is a worldwide problem. Environmental exposure is known to affect concrete strength in structures. While moisture affects rebound values by lowering them, carbonation does the opposite. The aim of the study was to determine the in-situ concrete strength of three bridge elements, namely, pier, abutment and deck and evaluate the environmental conditions such as moisture and abrasive forces on the near surface of concrete. Acknowledging that destructive tests on concrete are expensive and time consuming, this research used rebound hammer test -a non-destructive test (NDT) method. The easiness, simplicity and portability of the rebound hammer made it possible to cover all 13 highway bridges in a period of two months. All the study sites were under the management of Uganda National Roads Authority (UNRA). The choice of test locations was based on BS 1881: Part 202. Rebound hammer tests were done on main elements of bridges namely, decks, piers and abutments. Where possible a maximum of 3 test points were chosen for every single test location. In addition to the universal machine calibrations, the rebound values were correlated to the standard concrete cube compressive strength using old concrete factors. Preliminary results show that although there is significant variation in concrete strength in both pier and abutment, the variation is relatively more pronounced in latter. The paper recommends a combined methodology involving the use of several NDTs to come up with sufficiently reliable results. In conclusion, the development of a formal Bridge Management System (BMS) to enable collection of data through regular monitoring and inspection programs would facilitate prioritization of Maintenance, Repair and Rehabilitation (MR&R) strategies. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Highway bridges, concrete, environmental exposure, structural integrity, rebound hammer
in
Proceedings of the First International Conference on Construction Materials and Structures
pages
861 - 870
publisher
IOS Press
conference name
1st International Conference on Construction Materials and Structures
external identifiers
  • WOS:000353898900110
ISBN
978-1-61499-466-4
978-1-61499-465-7
DOI
10.3233/978-1-61499-466-4-861
language
English
LU publication?
yes
id
d16c42a3-ba99-45d9-90a4-1e9ae1509548 (old id 7432869)
date added to LUP
2015-06-24 14:39:58
date last changed
2016-04-16 08:35:45
@misc{d16c42a3-ba99-45d9-90a4-1e9ae1509548,
  abstract     = {Deterioration of concrete structures is a worldwide problem. Environmental exposure is known to affect concrete strength in structures. While moisture affects rebound values by lowering them, carbonation does the opposite. The aim of the study was to determine the in-situ concrete strength of three bridge elements, namely, pier, abutment and deck and evaluate the environmental conditions such as moisture and abrasive forces on the near surface of concrete. Acknowledging that destructive tests on concrete are expensive and time consuming, this research used rebound hammer test -a non-destructive test (NDT) method. The easiness, simplicity and portability of the rebound hammer made it possible to cover all 13 highway bridges in a period of two months. All the study sites were under the management of Uganda National Roads Authority (UNRA). The choice of test locations was based on BS 1881: Part 202. Rebound hammer tests were done on main elements of bridges namely, decks, piers and abutments. Where possible a maximum of 3 test points were chosen for every single test location. In addition to the universal machine calibrations, the rebound values were correlated to the standard concrete cube compressive strength using old concrete factors. Preliminary results show that although there is significant variation in concrete strength in both pier and abutment, the variation is relatively more pronounced in latter. The paper recommends a combined methodology involving the use of several NDTs to come up with sufficiently reliable results. In conclusion, the development of a formal Bridge Management System (BMS) to enable collection of data through regular monitoring and inspection programs would facilitate prioritization of Maintenance, Repair and Rehabilitation (MR&R) strategies.},
  author       = {Bakamwesiga, Hilary and Mwakali, Jackson and Sengendo, Stephen and Thelandersson, Sven},
  isbn         = {978-1-61499-466-4},
  keyword      = {Highway bridges,concrete,environmental exposure,structural integrity,rebound hammer},
  language     = {eng},
  pages        = {861--870},
  publisher    = {ARRAY(0x5e3f050)},
  series       = {Proceedings of the First International Conference on Construction Materials and Structures},
  title        = {Impact of environmental exposure on concrete strength in highway bridges in Uganda},
  url          = {http://dx.doi.org/10.3233/978-1-61499-466-4-861},
  year         = {2014},
}