Random behavior of concrete C45/55 XF2 used for prefabricated pre-stressed bridge beams is described on the basis of evaluating a vast set of measurements. A detailed statistical analysis is carried out on 133 test re...Random behavior of concrete C45/55 XF2 used for prefabricated pre-stressed bridge beams is described on the basis of evaluating a vast set of measurements. A detailed statistical analysis is carried out on 133 test results of cylinders 150 ~ 300 mm in size. The tests have been running in laboratories of the Klokner Institute. A single worker took all specimens throughout the period, and the subsequent measurements of the static modulus of elasticity and the compressive strength of the concrete were performed. The measurements were made at the age of 28 days after specimens casting, and only one testing machine with the same capping method was used. Suitable theoretical models of division are determined on the basis of tests in good congruence, with the use of Z2 and the Bernstein criterion. A set of concrete compressive strength （carried out on 133 test results of cylinders 150 ~ 300 mm after test of static modulus of elasticity） shows relatively high skewness in this specific case. This cause that limited beta distribution is better than generally recommended theoretical distribution for strength the normal or lognormal. The modulus of elasticity is not significantly affected due to skewness because the design value is based on mean value.展开更多
Bridges, especially highway bridges, are a key factor in nations’ development and flourish. Thus, great care should be taken to maintain and inspect their safety and serviceability. An immediate repair will prevent t...Bridges, especially highway bridges, are a key factor in nations’ development and flourish. Thus, great care should be taken to maintain and inspect their safety and serviceability. An immediate repair will prevent the loss of life and vehicles damage while crossing underpass and overpassing the heavy deteriorated bridges. Reinforced or pre-stressed concrete bridge girders become structurally deficient because of severed reasons including, increasing in the load requirements, corrosion of pre-stressing strands or reinforcement bars and collision of over-height trucks with the bulb of the concrete girders. The purpose of this case study is to evaluate and assess the damages of the highway bridges in Jordan. Since there is no mandatory program in Jordan for inspection of bridges and evaluating their conditions, this paper presents an inspection and assessment of two highway bridges along the desert highway which is the essential nerve connecting Jordan cities, and it also serves as an international road between many middle east countries. These two Bridges have never been investigated or checked since their construction in the late 1980s. The study results showed that the main factor causing the deterioration of these bridges is the collision of the over-height trucks with their elements. Relying on the collected data, solutions and repair methods were introduced to rehabilitate these bridges and assure their structural safety.展开更多
文摘Random behavior of concrete C45/55 XF2 used for prefabricated pre-stressed bridge beams is described on the basis of evaluating a vast set of measurements. A detailed statistical analysis is carried out on 133 test results of cylinders 150 ~ 300 mm in size. The tests have been running in laboratories of the Klokner Institute. A single worker took all specimens throughout the period, and the subsequent measurements of the static modulus of elasticity and the compressive strength of the concrete were performed. The measurements were made at the age of 28 days after specimens casting, and only one testing machine with the same capping method was used. Suitable theoretical models of division are determined on the basis of tests in good congruence, with the use of Z2 and the Bernstein criterion. A set of concrete compressive strength （carried out on 133 test results of cylinders 150 ~ 300 mm after test of static modulus of elasticity） shows relatively high skewness in this specific case. This cause that limited beta distribution is better than generally recommended theoretical distribution for strength the normal or lognormal. The modulus of elasticity is not significantly affected due to skewness because the design value is based on mean value.
文摘Bridges, especially highway bridges, are a key factor in nations’ development and flourish. Thus, great care should be taken to maintain and inspect their safety and serviceability. An immediate repair will prevent the loss of life and vehicles damage while crossing underpass and overpassing the heavy deteriorated bridges. Reinforced or pre-stressed concrete bridge girders become structurally deficient because of severed reasons including, increasing in the load requirements, corrosion of pre-stressing strands or reinforcement bars and collision of over-height trucks with the bulb of the concrete girders. The purpose of this case study is to evaluate and assess the damages of the highway bridges in Jordan. Since there is no mandatory program in Jordan for inspection of bridges and evaluating their conditions, this paper presents an inspection and assessment of two highway bridges along the desert highway which is the essential nerve connecting Jordan cities, and it also serves as an international road between many middle east countries. These two Bridges have never been investigated or checked since their construction in the late 1980s. The study results showed that the main factor causing the deterioration of these bridges is the collision of the over-height trucks with their elements. Relying on the collected data, solutions and repair methods were introduced to rehabilitate these bridges and assure their structural safety.
