Analysis on the Effects of External Temperature and Welding Speed on the Safety of EVA Waterproofing Sheet Joints by Hot Air Welding.

This study analyzes the optimal seasonal ambient temperature during welding and welding speed conditions for securing high tensile strength of ethylene vinyl acetate (EVA) waterproofing sheets bonded for roofing, installed by hot air welded joints (overlaps). Seven separate ambient temperature conditions (-10, -5, and 0 °C for winter conditions, 20 °C for the normal condition, and 25, 30, and 35 °C for summer conditions) were set for the test variable and seven speed conditions (3, 4, 5, 6, 7, 8, and 9 m/min) for hot air welding. Based on these conditions, EVA sheet joint specimens were prepared, and the tensile strength of the joint sections was tested and measured.

Evaluation of Sheet-Coated Composite Waterproofing Joint Types by Analysis of Tensile Strength Change and Concrete Displacement Resistance Testing under Environmental Degradation.

Sheet-coated composite waterproofing (SCCW) have been developed to overcome the natural weakness of singly-ply coating or sheet waterproofing systems for roofing, but there are currently multiple types of SCCW joints. Conventional standard tensile strength testing results show that all SCCW joint types seem to pass the minimum requirement and current selection of SCCW type is dictated on the principle of 'higher tensile strength is better', but it has not been experimentally studied as to which type is the optimal to respond to environmental degradation while under the effect of zero-span tensile stress occurring during concrete joint displacement. In this study, five types of SCCW joints were tested: Overlap Bond (OB) type, Overlap Heated-Air Welding (OH) type, Butt Joint I Type (BI), Butt Joint T Type (BT), and Butt Joint Separation Movement Type (BS).

Oil Leakage Evaluation for Selection of Emulsion-Based Non-Curable Synthetic Polymer Rubberized Gel (ENC-SPRG) as Waterproofing Material in Underground Structures.

A revised oil leakage evaluation regime is proposed in response to the oil leakage problems of emulsion-based non-curable synthetic polymer rubberized gel (ENC-SPRG) used as a waterproofing material in concrete slabs of residential underground structures. Oil leakage from ENC-SPRG can cause significant economic and environmental damage. As ENC-SPRG waterproofing material is relatively new in the global waterproofing market, a systematic quality control for ENC-SPRG products being manufactured and exported globally is currently non-existent.