Effect of corrosion on compressive strength of structurally insulated panels

Abstract

Demand for new construction methods are triggered due to post tsunami rehabilitations, recent landslides, floods and present developments in the North-East etc. Structurally insulated panels (SIPs) are one such system, which expedite and ease the construction work. In Sri Lanka major cities are located along the coastal belt where corrosion is inevitable. Though corrosion is not an uncommon event, effect of corrosion on load carrying capacity of SIP panels is not well documented in published literature yet. Hence, present study focused on finding the effect of corrosion on load carrying capacity and to propose durability enhancement methods of SIPs. Corrosion-induced damage was simulated in the cementitious structurally insulated panels (CSIPs) by reducing the reinforcing steel volume. Experimental investigations were carried out for SIP panels where three were having GI meshes and the other three were with chicken meshes (40% reduced steel volume) as reinforcement. All panels were testedfor compressive strength after 28 days. Durability enhancement (delaying or preventing corrosion) of CSIPs was tested by casting four panels. One panel was kept as reference panel and other three were sprayed with 0.1M Nacl solution to accelerate corrosion. Among these three panels, one panel was applied with water proofing agent and other was coated with weather shield paint and another was left uncoated. These panels were tested for compression after three months of periodic wetting and drying with salt water. 27.4% reduction in load carrying capacity was observed with chicken mesh. Moreover load carrying capacity of CSIPs were enhanced by 17.5% with weather shield paint coated and by 38.8% with water proofing agent with reference to not treated-but periodically salt sprayed panel. In this paper, in addition to comparing the durability enhancement techniques, there costs were also compared before concluding the paper with recommendations.