Flexural behavior of normal and lightweight reinforced concrete hollow arch beams.

This research investigated the behavior of hollow normal and lightweight reinforced concrete arch beams. The experimental program consists of (8) simply supported arch beams specimens testing under a four-points load. For all specimens, the width (b) was 150 mm variable depth of 100-150 mm at mid-span, 1500 mm was the total length, 1400 mm was the effective span, and 466 mm was the shear span. It includes four groups (G1, G2, G3, and G4) to study the following parameter: curvature degree, replacement ratios of lightweight coarse aggregate (partially replacement of normal coarse aggregate by thermostone with different percentages of 50% and 75%, respectively), voids ratio, ultimate load, cracking load and strain distribution. Specimens were studied for comparisons between all beams (for hollow and solid beams). The result indicates that the curvature degree and voids ratio reduced the ultimate load while increases the maximum deflection of the normal reinforced concrete arch beam. For a replacement ratio of 50% normal coarse aggregate by thermostone for hollow beams with different curvature degrees, the ultimate load and maximum deflection decreases by about (9.9%-37.5%) and (14.24%-27.2%) respectively, compared with normal hollow concrete. While the replacement ratio of 75% normal coarse aggregate by thermostone for hollow beams with different curvature degrees, the ultimate load and maximum deflection decreased by about (42.86%-46.79%) and (16.26%-31.71%) respectively, compared with normal hollow concrete. [ABSTRACT FROM AUTHOR]