A blend of poly(lactic acid) (PLA) (70% by weight) and poly(3-hydroxybutyrate) (PHB) (30% by weight) with a solubilizing agent (PBAT) at four different concentrations (5%, 10%, 15% and 20% by weight per 100 parts of the blends) were investigated by FTIR, SEM, mechanical testing, water vapor permeability test and biodegradation studies. SEM showed that PBAT can improve the compatibility between PLA and PHB. The film show a great Oxygen transmission rate and Water vapor permeability property when the content of PBAT is 10%.

Although traditional steel-concrete composite beam has excellent structural characteristics, it cannot meet the requirement of quick disassembly and repair in the bridge. This article presents an experimental study on friction performance of damaged steel-concrete interface in recoverable composite beam connected by high-strength frictional bolts. A total of 21 specific split tests were carried out using different concrete strength, steel strength, and surface treatment of steel. The experimental results showed that the demountable high-strength frictional bolt used in composite beam has similar performance as in the bare steel structures. The initial friction coefficient and slip stiffness were measured to be 0.34–0.47 and 52.3–116.1 kN/mm, respectively. Friction performance of damaged interface was obtained, proving that friction coefficient and slip stiffness will not decrease after the first slip damage. It is also confirmed that shot blasted steel and concrete with higher strength were more suitable in the demountable composite beam.

Prefabrication of composites beam reduces the construction time and makes them easily to be assembled, deconstructed, and partially repaired. e use of high-strength frictional bolt shear connectors can greatly enhance the sustainability of infrastructure. However, researches about the concrete-steel friction behavior are very limited. To provide a contribution to this area, 21 tests were conducted to measure the friction coefficient and slip stiffness with different concrete strength, steel strength, and surface treatment of steel. An effective finite element model was developed to investigate the ultimate bearing capacity and load-slip characteristics of bolt shear connection. e accuracy of the proposed finite element model is validated by the tests in this paper.e results demonstrate a positive correlation between concrete strength and friction coefficient and better performance of shotblasted steel. It is also proved that high-strength frictional bolt has a 30% lower bearing capacity but better strength reserve and antiuplifting than the headed stud.