in order to lighten the prestressed concrete solid members, nowadays, it is possible to make use of the advantage of hpc (fc'>60 mpa) as well as replacing the solid section with a psc thin-walled section for certain members such as circular and box columns. using the strength theory of aci, a numerical procedure along with a computer program was developed for the analysis of such sections ...

16. Abstract Two prestressed high performance concrete (HPC) highway bridges were constructed in Texas utilizing concrete with 56 day design strengths of up to 97 MPa (14,000 psi). The utilization of HPC allowed for longer spans and larger girder spacing than typically used in conventional prestressed concrete bridges. An extensive research program was conducted to monitor the shortand long-ter...

Shrinkage can be critical factor for the design of structural members due to the length changes by the timedependent deformation. Given the high fluidity and different mixture proportions of SCC, the shrinkage of such concrete can differ from those of conventional concrete or HPC of normal consistency. Proper estimate of autogenous shrinkage of self-consolidating concrete (SCC) can provide engi...

In the mid 1990's the FHWA established a High Performance Concrete (HPC) program aimed at demonstrating the positive effects of utilizing HPC in bridges. Research on the benefits of using high performance concrete for bridges has shown a number of benefits. These include increased span capacities, or wider girder spacings (and hence a fewer number of girders); increased concrete compressive and...

In the precast structures, optimization of structural elements is of great interest mainly due to a more rationalized way that elements are produced. There are several elements of precast prestressed concrete that are objects of study in optimization processes, as the prestressed joist applied in buildings slabs. This article inquires into cost minimization of continuous and simply supported sl...

With the extensive use of self-consolidating concrete (SCC) worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded re...

Abstract The combination of low clinker high-performance concrete (LCHPC) and ultra-high modulus (UHM) carbon fibre reinforced polymer (CFRP) tendons was recently proposed for prestressed structural elements. 70% reduction in cement content resulting limited creep shrinkage the LCHPC comparison to a conventional (HPC) very high UHM-CFRP tendon stiffness (> 509 GPa) were expected impact mecha...

The hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier were researched. The effects of the prestressed tendon ratio, the longitudinal reinforcement ratio, and the stirrup reinforcement ratio on the hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier have been obtained with the fiber model analysis method. The analysis show...

D analyses of structures responding elastically to ground motions recorded during severe earthquakes have shown that the theoretical response inertia loads are generally significantly greater than the static design lateral loads recommended by codes. Hence, structures designed for the lateral earthquake loads recommended by codes can only survive severe earthquakes if they have sufficient ducti...

In this paper, the bi-directional evolutionary structural optimization (BESO) method is used to find optimal layouts of 3D prestressed concrete beams. Considering the element sensitivity number as the design variable, the mathematical formulation of topology optimization is developed based on the ABAQUS finite element software package. The surface-to-surface contact with a small sliding between...