IV. BRIDGE ENGINEERING

A. COMPLETED PROJECTS
1. Preparation of Draft Specification for use of High Performance Concrete (HPC) for Pavement and Bridges made with indigenously available materials (B-32)
Duration

April 2000 to July 2002
(i) Central Road Research Institute, New Delhi (R)
(ii) Ministry of Shipping Road Transport & Highways (S)

 

Present Status and Progress
The final report was submitted to the Ministry after incorporating its observation. Subsequently it was further sent to the experts for their comments. Finally the extract of the report along with the comments of the experts has been sent to IRC so that the findings may take place in the guidelines for the use of HPC being formulated by IRC.
 
Findings/ Conclusions
The recommendations for the use of HPC for Roads & Bridges works are enclosed herewith. However, some of the basic features of the research scheme are:

(i) Laboratory investigation has been carried out using OPC 43 grade for M40 grade concrete for pavements and OPC 53 grade for M60 grade cement for bridges.

(ii) Fly ash samples from Dadri plant and Talcher plant have been used in the proportion of 15% by weight of cementitious material.

(iii) Silica fume named “Elkem” has been used in proportion of 10% by weight of cementitious material in the study.

(iv) Superplasticizers namely “SP3000 (G)” has been used in proportion of 0.6 – 2.0% by weight of cementitious material in the study.
 
Recommendations

The HPC pavement are found to be having longer service life as compared to conventional concrete pavement made with ordinary Portland Cement of 43 or 53 grade. Sequential construction procedures for rigid pavements are given in IRC: 15 – 2002. The same may be adopted for HPC pavements. There is not any major change in the construction of HPC roads using HPC except the addition of defined quantities of mineral and chemical admixtures as suggested in the present specification. The difference is only the mixing procedure of Portland cement, fine aggregate, coarse aggregate, silica fume and/or fly ash.

Flyash and silica fume which may be as health hazard as cement, slag and other reactive siliceous particles, if not handled properly. These shall be used with proper care and bags shall be opened when required, but used within a period of six months. IS: 456-2000 and IRC: 15-2002 shall be followed for HPC as is followed for conventional concrete of equivalent strength. Tools, equipments and appliances required for concrete pavement construction should be as per IRC: 43-1972 and IRC: 15-2002. For the joint spacing, types of sealant, pre-moulded joint filler materials and any other aspect not covered in the present specifications on HPC pavement, IRC: 15-2002 / IRC: 58-2002 may be referred.

Grade I fly ash as per IS: 3812 – 1981 upto 15 percent by weight of total cementitious material and silica fume as per IS: 456-2000 up to 10 per cent by weight of cementitious material are found most suitable for making high performance concrete. Chemical admixtures as per IS: 9103-1979 up to 2.0 percent by weight of cementitious material may be used to attain required workability and durability.

 
Reports/Publications
Final report has been submitted to the Ministry