Highway Research Record

IV. BRIDGE ENGINEERING
NEW PROJECTS
Dynamic Response of Prestressed Concrete Bridges

Date of Start:April 2004 to March 2007
Central Road Research Institute, New Delhi (R)

Scope and Objectives
The objective of the study is to develop a realistic modelling of prestressed concrete bridges, which is capable to take into account the time dependent non-linear effect of creep and shrinkage. Based on this modelling, computer software will be developed. Further study, particularly based on dynamic tests in linear / non-linear field is proposed to be carried out to find out the dynamic response of PSC bridges.

Methodology
(i) Literature survey
(ii) Mathematical modelling of long term time-dependent factors viz creep and shrinkage which influence the response of     prestressed concrete structures
(iii) Mathematical modelling of prestressed concrete
(iv) Development of a computer software, to study the behaviour of the structure analytically, based on the above modeling (v) Validation of the software using the data available in the literature / laboratory studies
(vi) Case studies for response of prestressed concrete structures under dynamic loading at any time during its service
(vii) Conclusions and preparation of report

Conclusions
Various analytical models to predict the creep of shrinkage have been suggested by the various researchers. These prediction models have been grouped into the following three broad categories:
(i) Empirical models
(ii) Research based models
(iii) Codal models
These prediction models have been described in the interim report No.CRRI/BIE/OLP-0409(01)/2004-05 titled ‘Prediction of creep and shrinkage in concrete’. The predictions obtained by these analytical models have been compared with the experimental results. The results of comparison are also given in the above mentioned interim report. Based on the comparison, GL2000 prediction model has been selected for use in the future study.

Significance / utilization potential
(i) This work will be of high academic research, which can be extended for technical uses.
(ii) This project is beneficial to the prestressing industries as well as the designers of the prestressing structures.
(iii) Computer software will be developed, which will be useful to researchers and designers.

Reports / Publications
1. Goel, R. and Kumar, R. (2004), ‘Prediction of creep and shrinkage in concrete’, Report No. CRRI/BIE/OLP-0409     (01)/2004-  05, Central Road Research Institute, New Delhi.
2. Goel, R. and Kumar, R. (2004), ‘Computer program for prediction of creep and shrinkage in concrete’, Report No.     CRRI/BIE/OLP-0409 (02)/2004-05, Central Road Research Institute, New Delhi.
3. Goel, R., Kumar, R. and Paul, D.K., ‘A comparative study of various creep and shrinkage prediction models for concrete’,     Sent for publication in ASCE Materials in Civil Engineering.