Concrete using electric furnace oxidation slag as coarse aggregate (EFG) is brittle due to expansion of EFG inside the concrete upon heating. In this study, composition analysis and volumetric measurement of EFG were conducted for each heating time at 500℃, and it was found EFG doesn’t expand at heating times of 2 hours. The mechanical properties of concrete with each replacement ratio of EFG at each heating times at 500℃ were also measured, and it was found concrete with EFG replacing 20% of the coarse aggregate didn’t lose its mechanical properties even when the heating time was 4 hours.

Mortar mixed with expanded polystyrene beads and electric arc furnace oxidizing slag (“beads slag mortar”) can be used as a broadband electromagnetic wave absorber by applying vibration before curing. In this study, the effects of vibration frequency and time during manufacturing, as well as water-cement ratio on aggregate distribution within the cross-section of beads slag mortar were investigated. It was found that the higher the vibration frequency, the shorter the vibration time and the lower the water-cement ratio required to achieve the aggregate distribution that results in a broadband electromagnetic wave absorber.

In the 2016 countermeasures for long-period ground motions (LPGMs) caused by a major Nankai Trough earthquake, the response spectrum method (RSM) specified in Ministry of Construction notification Vol. 2009 was excluded due to the lack of an established methodology. However, RSM enables a comprehensive evaluation of structural safety using design response spectra, independent of individual earthquake characteristics. This study proposes an RSM approach that considers the characteristic changes of lead rubber bearings and oil dampers due to repeated deformation. By comparing it with nonlinear time history analysis, the study examines their correspondence and evaluates the effectiveness of the proposed method.

Solving the equations of Timoshenko beam theory is not easy. Therefore, many form factors regarding shear have been proposed. In this paper, we propose a method that satisfies the principle of superposition and separates a beam into a bending side and a shear side. We then divide the equations of elasticity theory into two states. Each equation is reduced from the original equation, making it easier to solve the equation. The resulting shear form factor did not depend on Poisson’s ratio, unlike those previously proposed.

In this paper, a new bolt axial force reduction coefficient was calculated and evaluated to assess the reduction in bolt axial force due to both increased cable tension and aging, with the aim of rationalizing the design methodology for intermediate joints. First, the change in bolt axial force due to increased cable tension was determined experimentally. Second, the coefficient of reduction of bolt axial force due to aging was calculated from the experimental results. Finally, a new bolt axial force reduction factor was calculated considering the above two experimental results and compared with the current bolt axial force reduction coefficient.

This paper reports on an evaluation method of performance of rotational resistance of traditional wooden half tenon joints with dowel (Hana-sen). We constructed mechanical models for both the positive and negative directions based on the results of full-scale bending experiments and examined evaluation formulas for initial stiffness and yield strength. From the comparison and examination of the estimated values obtained from the evaluation formula and the experimental results, it was confirmed that a certain degree of consistency was achieved. And the yield strength of the calculated values tended to be similar to that of the real phenomenon.

Partial compressive performance of wood-based material needs to be obtained for structural design. Orthogonally laminated materials have been developed in recent years. An area in the additional length is and is not deformed under the partial compressive load perpendicular and parallel to grain, respectively. Therefore, the deformative constraint in the area occurs in the orthogonally laminated materials, which might improve the partial compressive performance. This effect was experimentally and quantitatively evaluated using veneer laminated specimens and theoretically evaluated via a mechanical model based on Pasternak model. Consequently, the improvement in the stiffness was demonstrated.

A static loading test with high spatial resolution measurements was performed for an RC flexural wall. Its deformation mechanics up to rebar yielding were investigated to find that flexural and anchorage deformation components are dominant and that increase in stress in the compression area at the critical section due to the diagonal crack occurrence is an essential phenomenon to estimate the deformations. The corresponding phenomenon was then well simulated quantitatively by assuming the concrete in the compression area sustains instead the moment of tensile rebars released due to the diagonal crack occurrence.

This study investigates pile-caps with eccentricity in two horizontal directions under loading that induces tension at the beam bottoms. Cracks developed between the tips of the pile bars on the tension side and those of the column bars on the compression side. Measured strengths were lower than those from conventional flexural analyses, particularly when the pile-cap depth was small and the anchorage lengths of the pile bars were short, despite sufficient anchorage-to-diameter ratio. The observed strengths were reasonably estimated by assuming a failure plane consistent with the observed cracks.

A method to calculate the balanced failure strength of unbonded PC interior beam-column joints by adding the effects of unbonding and openings to the theoretical equation for RC interior beam-column joints was proposed and its compatibility with the experimental results was verified. The prestress was considered to be an external force for the beam-column joint, and the tensile stress of the PC steel was assumed not to be generated on the hypothetical cross section, and the voids caused by the openings are assumed to be numerous small openings evenly distributed throughout the hypothetical cross section.

In this paper, the effects of various variables on the sliding coefficient of a high-strength bolted friction joint of a plated thin steel plate are investigated. First, slip experiments were conducted to investigate the effects of plate thickness and number of bolts on the slip coefficient. Next, FEM analysis was performed to compare the results with the experiments. As a result, it was found that the coefficient of slip became smaller as the thickness of the bracing became thinner, and the coefficient of slip became smaller as the number of bolts increased, both in the experiment and FEM analysis.

The horizontal stiffness method (the HS method) is proposed as an accurate approach to evaluate the effective length factor of columns when a frame with long columns buckles in a sidesway mode, utilizing the horizontal stiffness derived by the first-order analysis. A parametric study was conducted to investigate the accuracy of the method. Based on the numerical results, the HS method can evaluate the effective length factor of a long column in a frame with an accuracy of 5~6%. The A_i distribution (the Japanese design shear force distribution) is recommended for the story shear force in the first-order analysis.

In this study, heating experiments were conducted on structural glued laminated beams for more than 60 minutes, and the variations in charring depth and residual cross-section were discussed. It was found that the variation of charring depth generally followed a normal distribution. By assuming that the corners in the residual cross-section were circular arcs, the experimental values of the remaining ratio of section modulus could be tracked with good accuracy. By calculating the charring rate as the average value added to the standard deviation, the calculated value was close to the minimum experimental value of remaining ratio of section modulus.

This study investigated the deflection behaviour of a composite beam with a glulam beam and an RC slab in a fire. Load-bearing fire tests were conducted on a simply supported glulam beam and a composite beam. Connecting the glulam beam and the RC slab extended the fire resistance period by 20 minutes compared to the glulam beam. This paper proposes a method for calculating the degree of composite effect in a fire. Change in the degree of composite effect is one of the factors that determine the deflection behaviour of composite beams.