This study applied WPVC composite materials as log elements and investigated the lateral load resistance capability using two first log-foundation connections (LS-SST and LF-AB) and two corner joints (CJ-SN and CJ-SHL) subjected to monotonic and cyclic loads via an experimental approach. The obtained results indicated that the load resisting behavior of the connections was different, although the load bearing area of the connections was similar. The LF-SST connections experienced a brittle failure, while LF-AB showed a ductile failure. The premature failure occurred at the hollow web section of orthogonal log elements for both corner joints. The presence of a metal fastener directly affected the lateral load resisting behavior of the connection, especially under cyclic loading.The equivalent energy elastic plastic (EEEP) and hysteretic parameters were determined, indicating that LF-AB provided 1.8 times of ductility ratio and 35.4% of hysteretic energy higher than LF-SST, and that CJ-SHL had 3.1 and 2.8 times of monotonic and cyclic stiffnesses higher than CJ-SN. In comparing the experimental results with timber log elements, the hollow section of the WPVC composite log element had a negligible effect on load resisting behavior; however, it significantly affected the load resisting capacity, stiffness, damping, and premature failure. The experimental data and the proposed parameters will be useful for the further design of WPVC composite log houses.

The cross-section design of wood/polyvinyl chloride composite log-wall panels was studied for effects on compressive load, thermal and acoustic properties. Variation in the slenderness ratio (2, 4, 8, 10 and 12) on compressive load was also included. Two parameters of log-wall cross sections consisting of web thickness (3.5, 7.0 and 10.0 mm) and flange spacing (45, 60 and 90 mm) were also investigated. Experimental results indicated that higher web thickness and lower flange spacing of wood/polyvinyl chloride composite log-wall cross sections increased the ultimate compressive load and noise reduction. However, lateral deflection and thermal resistance decreased. Increasing the slenderness ratio of the log-wall panels resulted in lower ultimate compressive load and higher lateral deflection. Empirical equations for predicting the ultimate compressive load of wood/polyvinyl chloride composite log-wall panels in practical uses were proposed regarding web thickness, flange spacing and slenderness ratio.

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This work experimentally determines the in-plane lateral load behavior of a full-scale WPVC composite log-wall, with and without additional through-bolts. The results indicate that the WPVC composite log-wall panel with through-bolts produced higher hysteretic parameter values in terms of strength and energy dissipation than the log-wall without through bolts due to a reduction in wall uplift (48.2% for secant stiffness of cycle, 39.5% for hysteretic energy at the last displacement level). The WPVC composite log-wall panel with through-bolts presented better structural stability and was recommended for investigation. A finite element model (FEM) of a WPVC composite log-wall panel with through-bolts was created using beam elements as log-members and multilinear plastic links as connections, and was verified by the experimental results. The verified FEM was used for further parametric study of wall dimensions and first log-foundation locations. The parametric investigations indicated that increasing panel height and width unfavorably affected lateral load capacity, monotonic and cyclic stiffness, and energy dissipation. The cyclic stiffness decreased by 39% while energy dissipation increased by 78.8%, for the last displacement level when the wall height was increased from 2.350 m to 3.525 m. The cyclic stiffness and energy dissipation of a panel with a width of 6 m decreased 14% and 24.4% compared to a panel with a width of 3.5 m. Moreover, moving log-foundation connections from the original position to the edges of the panel improved performance under monotonic and cyclic horizontal loads; an increase in the number of log-foundation connections had an insignificant effect on panel behavior.

This paper presents the design concept, and monitoring results of the Resilient Nest which was participated in the Solar Decathlon Europe 2019 competition. The Resilient Nest has been designed as a lightweight rooftop house which can be placed on top of a row house in Bangkok, Thailand to respond an increased urban density. This additional rooftop house does not only increase the living space on an existing building, but it also ensures that the existing building become more viable, comfortable and eco-friendly. A solar energy, both electrical energy from photovoltaic panel and thermal energy from solar collector which are renewable energy, can accommodate the Resilient Nest rooftop as well as the existing building. The monitored results during 10 days competition results showed that the energy balance of the Resilient Nest was net positive of 171.81 kWh which was the highest value compared to other 9 competitors. The Resilient Nest generated 277.78 kWh as the first runner-up for the Energy generation. The power consumption for the HVAC system of the Resilient Nest during 10 days was only 37.65 kWh. Comparing to the suitable air conditioned house recommended by the Government Public Relations Department of Thailand, the Resilient Nest consumed over 14 times less energy because of its high performance thermal insulation, heat recovery system and solar thermal system. The low HVAC power consumption gave high performance for indoor comfort. As a result, the Resilient Nest won a second place in Comfort conditions contest.