Full-scale test of precast prestressed concrete double-tee girder for rural bridges

Abstract

Increasing the number of small and medium-sized bridges is a need to improve accessibility in rural areas of the Mekong River Delta of Vietnam. Many types of bridge structures can be the suitable selection for rural bridges, on which the overall load of the operating truck is about 100kN. An objective of this paper is to propose a double-tee (DT) girder with the span length varying from 12 m to 15 m for the rural bridge types B and C in the Vietnamese standard. New concrete aggregate using crushed sand and fly ash for the DT girders is also examined to solve the scarcity of natural sand and environmental problem from industrial waste. A full-scale DT girder with a span length of 12 m is tested to confirm the capacity of the proposed design. Result finds out that the concrete sand, which the natural sand is replaced by 90% of the crushed sand and 10% of the fly ash by weight, could be well applied for the proposed DT girders. Another finding is a linear elastic uncracked response of the tested DT girder under loads of a rural vehicle and concrete blocks of 306kN. Therefore, the proposed DT girders are suggested to the rural bridges.

Recycled concrete bridge engineering based on artificial intelligence algorithm

“…Refer to the following flow chart for the manufacturing steps of RC beam specimens:Fig. The measures to improve the durability of concrete bridge structures from the quality of RC materials mainly include: selecting appropriate cement according to the requirements of environment, climate, strength, etc; In order to improve the durability of the bridge and reduce the construction cost, mineral admixtures such as fly ash and silica fume are used; Use aggregates with good particle shape and grading to improve the crack resistance of concrete, and avoid using active aggregates such as sea sand; In order to improve the compactness, workability and frost resistance of concrete, corresponding admixtures should be used [11][12].…”