Dimensionnement des tabliers de ponts courants au moyen de l'ordinateur

1979 ◽  
Vol 6 (3) ◽  
pp. 343-354
Author(s):  
Marc Thenoz ◽  
Claude Bidaud

This paper presents the electronic computer programmes used for the design of standard bridge superstructures by the SETRA (Service d'Etudes techniques des Routes et Autoroutes) of the French Department of Public Works. There is one particular programme for each bridge type. Through these programmes, concrete widths and depths and steel reinforcement are calculated for reinforced concrete beam and slab bridges, and prestressing is designed for prestressed concrete beam and slab bridges.Since February 1, 1962, 11 000 bridges have been designed with these varied and general programmes, suitable for most standard road and freeway overpasses. [Journal translation]

2014 ◽  
Vol 92 ◽  
pp. 74-83 ◽  
Author(s):  
Wanchai Yodsudjai

The applications of using fly ash-based geopolymer as a structural member and a repair materials in reinforced concrete structure was conducted. The optimum mix proportion of fly ash-based geopolymer concrete using for structural beam and fly ash-based geopolymer mortar using for repair material were developed. The flexural behavior of fly ash-based geopolymer reinforced concrete and the durability aspect namely the corrosion of steel reinforcement were investigated using the electrical acceleration. For the repair purpose, the fundamental properties; that is, compressive strength, flexural strength, bonding strength between fly ash-based geopolymer mortar and mortar substrate, setting time and chloride penetration were investigated. Also, the durability of conventional reinforced concrete beam repaired by the fly ash-based geopolymer mortar comparing with the comercial repair mortar was investigated. The behavior of the fly ash-based geopolymer reinforced concrete beam was similar to that of the conventional reinforced concrete beam; however, the corrosion of the steel reinforcement of the fly ash-based geopolymer reinforced concrete beam was higher than that of the conventional reinforced concrete beam. The fundamental properties of the fly ash-based geopolymer mortar were not different from that of the commercial repair materials; however, the durability of the reinforced concrete beam repaired by the fly ash-based geopolymer mortars performed a little lower than that of repaired with the commercial repair motar and also the control reinforced concrete with no repair. As a result, even there will be still a need of improvement there was a good tendency for using the fly ash-based geopolymer as the structural member and the repair materials.


2013 ◽  
Vol 486 ◽  
pp. 211-216
Author(s):  
Jan Zatloukal ◽  
Petr Konvalinka

The flexural behavior of FRP (Fiber Reinforced Polymer) reinforced concrete beam has been the topic of intensive previous research, because of the spread of use of modern FRP composite materials in the building industry as concrete reinforcement. The behavior of FRP reinforced member is different from the one reinforced with regular steel reinforcement, mainly because of vast difference between moduli of elasticity of FRP composite reinforcement bars and steel. This difference results in the fact that conventional design methods used for years in the field of reinforced concrete structures using steel reinforcement give poor results if attempted use with FRP reinforced structural members. Results of conventional methods are so poor that use of such methods would be dangerous they tend to overestimate load carrying capacity and underestimate deformations both resulting in unsafe predictions. This paper points to formulating easy to use and comprehensible method of predicting moment capacity of FRP reinforced concrete beams subjected to bending loading and validation of the proposed method via set of experiments.


2016 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Agostinho Francisco Pinto ◽  
Sri Murni Dewi ◽  
Devi Nurlinah

Need for the use of reinforced concrete in housing construction will increase along with the rapid population growth. This increases the need for steel reinforcement as a major component. The increase in need for steel reinforcement will trigger a price increase so that it becomes expensive and scarce. Iron ore as a raw material for making steel reinforcement is a mineral that can not be renewed. Therefore, efforts to use alternatives to steel reinforcement in concrete. Bamboo has good mechanical properties and a high ratio between strength and weight. Bamboo has a tensile strength is high, between 100-400 MPa, nearly matching the tensile strength equivalent to steel reinforcement ½ to ¼ of iron ultimate voltage (Widjaja, 2001) and (Surjokusumo and Nugroho, 1993) showed similar results and by the Moriscos, 1996 that the tensile strength of bamboo can reach 1280 kg / cm2. Bamboo can be used as the material of reinforced concrete. This study aims to determine the capacity of the bending beam with reinforcement of bamboo, bamboo reinforced beam deflection capacity. This experiment is a concrete beam bending test. The results showed that bamboo reinforced concrete beam has a maximum capacity reached 56.61% of the maximum capacity of steel reinforced concrete.


2017 ◽  
Vol 62 (3) ◽  
pp. 1915-1922 ◽  
Author(s):  
P. Selvachandran ◽  
S. Anandakumar ◽  
K.L. Muthuramu

AbstractCarbon Fiber Reinforced polymer (CFRP) bars are weak in yielding property which results in sudden failure of structure at failure load. Inclusion of non-pretensioned steel reinforcement in the tension side of CFRP based prestressed concrete beam will balance the yielding requirements of member and it will show the definite crack failure pattern before failure. Experimental investigation has been carried out to study the deflection behavior of partially prestressed beam. Experimental works includes four beam specimens stressed by varying degree of prestressing. The Partial Prestressing Ratio (PPR) of specimen is considered for experimental works in the range of 0.6 to 0.8. A new deflection model is recommended in the present study considering the strain contribution of CFRP bar and steel reinforcement for the fully bonded member. New deflection model converges to experimental results with the error of less than 5% .


2015 ◽  
Vol 744-746 ◽  
pp. 283-287
Author(s):  
Can Liu

Inner transverse prestressed bars were used to enhance the shear capacity of concrete beams in this paper, which can be used in transformer beams to reduce the sectional size. Two transversely prestressed one ordinary concrete beams were tested and calculated by finite element method, and the following conclusions can be drawn: (a)The shear capacity of transversely prestressed concrete beam increase rapidly with the increase of the prestressing force level, which means that prestressing force level has a great influence on the shear capacity of transversely prestressed concrete beam. (b) The transverse prestressing bars can efficiently enhance the anti-crack performance of the reinforced concrete beams.


2011 ◽  
Vol 368-373 ◽  
pp. 108-113
Author(s):  
Can Liu ◽  
Bo Wu ◽  
Kai Yan Xu

This paper presents a method that using inner transverse prestressing bars to enhance the shear capacity of concrete beams, which can be used in new transformer beams to decrease the sectional dimensions. Four transversely prestressed concrete beams and one ordinary reinforced concrete beam were tested. The nonlinear finite element method was applied to analyze them, and the following conclusions can be drawn: (a) The transverse prestressing bars can efficiently increase the shear capacity and failure load of the reinforced concrete beam, the improvement effect is more obvious when exerting the prestressing force on them properly. (b) On the whole, the simulated load-deflection relationships and failure loads of the five specimens agree well with the corresponding tested load-deflection relationships and failure loads. It indicated that the FE models used in this paper predict the structural behavior of the transversely prestressed concrete beams satisfactorily. (c) From the contour of first principal stress, it can be seen that the transverse prestressing bars can efficiently enhance the shear crack resistance of the reinforced concrete beams, if the area of transversely prestressing bars is almost same, the transverse bars with smaller diameter and smaller spacing will be better. It agrees well with the test results.


Author(s):  
Peter P. Gaigerov

For large-span reinforced concrete beam structures developed by the method of determining the camber due to the prestressing of a steel rope on the concrete. Performed numerical experiments to study the impact of various schemes layout prestressed reinforcement without bonding with concrete on the distribution of the relief efforts along the path of the reinforcement.


Sign in / Sign up

Export Citation Format

Share Document