J. Daniel Ronald Joseph

Bio: J. Daniel Ronald Joseph is an academic researcher from Structural Engineering Research Centre. The author has contributed to research in topics: Sandwich-structured composite & Precast concrete. The author has an hindex of 3, co-authored 10 publications receiving 58 citations. Previous affiliations of J. Daniel Ronald Joseph include Council of Scientific and Industrial Research & Central Electro Chemical Research Institute.

Experimental studies on through-thickness shear behavior of EPS based precast concrete sandwich panels with truss shear connectors

Abstract: Effective use of building materials for achieving sustainable construction is of prime importance today due to fast depletion of the natural resources by the construction industries for obtaining raw materials and aggregates. Precast insulated concrete sandwich panels (CSPs) consisting of two reinforced concrete wythes, an Expanded Poly-Styrene (EPS) core and truss-type shear connectors can be considered as an innovative construction material for acting as load bearing walls and floors in building systems. The two wythes are connected by the shear connectors through the EPS core for transferring shear forces (henceforth called as through-thickness shear) between the wythes and achieving composite action in the panels. In this paper, details of experimental studies conducted on small-scale precast CSP specimens under through-thickness shear loading are presented. The major parameters considered in the experimental program were the thickness of EPS core, gap between the wythes (in CSPs without EPS core), presence/absence of EPS core and number of shear connector lines. The effect of the major parameters on the failure mode, through-thickness shear strength, load vs relative displacement (between top and bottom wythes) behavior and load vs strain behavior of the CSPs are presented and discussed. The test results indicate that the through-thickness shear strength and behavior of the CSPs are significantly influenced by the parameters considered. Reduction in thickness of the EPS core and presence of the EPS core improved the through-thickness shear strength of the CSPs.

Flexural behavior of precast concrete sandwich panels under different loading conditions such as punching and bending

Abstract: Precast concrete sandwich panels having two wythes separated by a core may serve dual purposes of transferring load and insulating. Research studies with respect to flexural behavior of these panels under four-point bending are available in the literature. Nevertheless, experimental and analytical studies with respect to flexural behavior of concrete sandwich panels under punching load are not found. In this paper experimental and analytical studies carried out to understand and compare flexural behavior of concrete sandwich panels under two different loading conditions such as punching and four-point bending are presented and discussed. Experimental study indicates that, type of loading conditions affects the flexural behavior of the concrete sandwich panels significantly. The panel subjected to punching load failed in flexural mode, and its behavior is similar to conventional RC slab. Under four-point bending the panel failure is attributed to failure of concrete by combined effect of shear and flexural stresses. For both types of loading conditions, analytically predicted cracking moment is comparable to the experimental cracking moment. Further experimental and analytical studies are required in this area to develop design guidelines for practical applications of these types of panels under different loading conditions.

Experimental study on the flexural behavior of insulated concrete sandwich panels with wires as shear connectors

Abstract: Composite structural elements can serve dual purposes of transferring the load and insulating the buildings. This paper presents and discusses the results of experimental study carried out to understand the flexural behavior of prototype precast insulated concrete sandwich panels using truss-shaped continuous shear connectors. Experimental study consisted of four prototype concrete sandwich panels tested under four-point bending simulating one-way slab action. Panel thickness and size of wire mesh used as reinforcement in concrete wythes are the major parameters considered. Test results indicate that the truss-shaped shear connectors are effective to achieve composite action of the panels until failure. Test results also indicate that the panel thickness affects the flexural load carrying capacity, and size of wire mesh affects the ductility. Experimental and analytical studies are required in this area towards developing guidelines for design of concrete sandwich panels for field applications.

Lightweight structural cement composites with expanded polystyrene (EPS) for enhanced thermal insulation

Abstract: The development of Expanded Polystyrene (EPS) concrete involves two major concerns: (a) poor strength resulting in the EPS concrete unsuitable for structural applications, and (b) segregation of the ultra-light weight of EPS during mixing (EPS is approximately 100 times lighter than concrete). Though EPS displays high insulation (thermal conductivity ≈ 0.04 W/m-K), these issues limit its usage in concrete. This study aims to develop a lightweight-EPS cement composite (LECC) having enhanced insulating capacity as well as satisfactory compressive strength for structural applications. To mitigate the deteriorating effect of EPS on strength, the LECC is developed using the base material of ultra-high performance concrete (UHPC). EPS beads of 3–5 mm diameter are mixed in UHPC in five proportions by volume of 0, 16, 25, 36, 45% and the resulting composites are tested for mechanical and thermal properties. Microstructural characterization is performed using micro-computed tomography (μCT). The choice of the UHPC ingredients proportion is found successful in achieving a balance between an optimum viscosity and satisfactory workability for uniform dispersion of EPS, confirmed by the flow values and μCT results. McLachlan's general effective media approximation, based on percolation theory, is used to homogenize the composite and estimate its thermal conductivity with satisfactory accuracy. The LECC thus developed displays a strength 45 MPa with a corresponding density of 1677 kg/m3 and thermal conductivity of 0.58 W/m-K.

Performance of Concrete Beams Reinforced with Various Ratios of Hybrid GFRP/Steel Bars

Abstract: This paper aims to study the flexural behavior of concrete beams reinforced with hybrid combinations of GFRP/steel bars. To this purpose an experimental program was carried out on four concrete beams reinforced with Glass Fiber Reinforced Polymer (GFRP) and twelve hybrid GFRP/steel Reinforced Concrete (RC) beams. Flexural behavior of the tested beams such as stages of response, failure modes, crack patterns, stiffness, toughness and ductility were analyzed. The experimental results showed that depending on GFRP/steel reinforcement configurations, the behavior of hybrid GFRP/steel RC beams undergoes three or four stages, namely: pre-cracking stage; after concrete cracking and before steel yielding; post-yield stage of the steel bar until peak load and failure stage. Totally six failure modes of hybrid RC beams are reported depending on reinforcement rations and configuration. The effect of reinforcement configuration and ratio of GFRP to steel ( ρ g ) on the crack patterns, stiffness, ductility and toughness of hybrid RC beams are significant. Based on the non-linear deformation model, an analytical model has been developed and validated to determine the steel yielding moment and ultimate moment of hybrid GFRP/steel RC beams. It could be seen that the experimental values were in good agreement with the predicted values.