Experimental and numerical assessment of the flexural behaviour of semi-precast-reinforced concrete slabs

Abstract

Semi-precast-reinforced concrete slab system offers more economic method of construction as it minimises the need of formwork at site. The assembly of semi-precast slab system involves two steps: (1) casting of semi-precast slab at the yard and (2) overtopping of concrete at the site. One of the main factors that influence the performance of such slab system is the interface bonding between precast and overtopping concrete. Therefore, in order to better understand the performance of this slab system, a research was carried out to investigate the influence of surface treatment methodologies to the overall flexural behaviour through experimental and numerical studies. In total, five representative semi-precast slabs were constructed and tested to assess the flexural performance with different surface preparation methods and concrete overtopping. Further small-scale precast with overtopped concrete couplets and triplets were casted and tested as the representative semi-precast concrete slab types to examine the interface shear and tensile bond strength characteristics with those different surface treatments. The experimental results revealed that the surface treatment methods have influenced the flexural behaviour of the slabs, where the interface shear bond strength exceeds more than 1.0 MPa and the slab system behaves monolithically under flexural action. Moreover, numerical modelling technique for this slab system was developed based on the finite element framework to further analyse the overall flexural behaviour. Subsequently, good agreements between experimental and developed numerical model results were found. Finally, parametric analyses were performed to further assess the influences of concrete strengths, spans and reinforcement ratios on the safe imposed pressure applicable for this slab system.

Cracking Analysis of Precast – In Situ Reinforced Concrete Slab With Plastic Void Formers

“…Būdingiausios surenkamosios monolitinės perdangos plokštės su plastikiniais intarpais vietos, kuriose anksčiausiai susidaro plyšiai, yra atraminė zona (Hegger et al, 2003;Ji & Liu, 2020), plokštės surenkamajame sluoksnyje ties didžiausio lenkimo momento vieta (Mohamed et al, 2020) ir surenkamojo ir monolitinio betono sluoksnių jungtyje (Mohamed et al, 2020;Ibrahim et al, 2019). Irimas atraminėje zonoje ir betono sluoksnių jungtyje gali susidaryti dėl didelio lenkimo momento ir šlyties įtempių.…”

“…Kitų autorių tyrimų (Ibrahim et al, 2019;Stehle et al, 2011;Mohamed et al, 2020;Hegger et al, 2003) analizė parodė, kad galima išskirti tris tokio tipo plokščių darbo etapus. Pirmajame etape konstrukcija dirba tampriai, dar nėra pasireiškusios plastinės deformacijos.…”

“…8 paveikslas. Plokštės pleišėjimas didžiausio lenkimo momento vietoje(Mohamed et al, 2020) Figure8. Slab fl exural cracking(Mohamed et al, 2020) 9 paveikslas.…”

Behaviour of concrete composite slabs with truss type shear connectors of different orientation angle

“…It was reported that the ductility and toughness improved with the addition of steel fibre reinforced toppings to the precast concrete slab. Mohamed et al (2020) assessed the flexural performance of semi-precast slabs with in situ concrete slabs with different interface detailing and shear ties. The study reported that the type of surface treatment has pronounced influence on the flexural capacity of composite slab systems tested.…”

Deflection Analysis of Layered Slabs with Plastic Inserts

“…A number of sources [ 1 , 4 , 7 , 8 , 9 ] provide that at the initial service stage of loads affecting the above introduced structures, both layers work and deform together until loads reach 50% of bearing capacity. Conventional structural analysis applies to the previously mentioned slabs because the slab has the same load-bearing capacity as a monolithic reinforced concrete slab of the solid cross-section [ 3 , 4 , 10 , 11 ].…”