Pore structure characterization of hardened cement paste is important to concrete mechanical and transport properties. Hence, we apply indirect methods (NS, MIP, and NMR) and direct methods (XCT, FIB/SEM, and HIM) to provide a general view of the pore structure of hardened cement paste. The results show that the 3D pore network of hardened cement paste is isolated in microscale yet is largely connected by large capillary pores, small capillary pores, and microcracks in nanoscale. In indirect methods, MIP and NMR have a wide measurement range and permit observing most of the porous volume with an average porosity of 8.4–9.9% of hardened cement paste. In contrast, direct methods have a relatively narrow measurement range and thus lead to a large porosity scattering of 1.8–16.4%. The pore size distribution (PSD) curves by indirect methods show that the pore structure is mainly concentrated in three sections of 1–10 nm, 10–100 nm, and around 10 μm, which correspond to the imaging range of HIM, FIB/SEM, and XCT. However, FIB/SEM implies that the most porous part of hardened cement paste (10–100 nm) is underestimated by MIP due to the “ink-bottle” effect. Another “underestimation” of NMR is because C-S-H gels swell during the wetting, and the swelling separates the capillary pores into smaller ones. The microcracks induced by sample preparation contribute 0.1-0.2% (XCT) and 4.5–8.1% (FIB/SEM) of porosity to the porous volume of cement paste, but they have limited influence on the pore size distribution and pore connectivity.

Parallel strand bamboo (PSB) is a latest construction material; to know more about mechanical properties of PSB, 5 groups of specimens with difference only in bolt diameter were designed to study the impact of the fastener diameter on embedding strength perpendicular to grain of PSB. Based on the tested result, the feasibility for PSB of the theoretical equation in the American code and European code on embedding strength predication was assessed. A controlled displacement was used to load till specimen failure, the stress‐displacement curve of all specimens was obtained in terms of the tested results, and the yielding tested strength based on 5% bolt diameter offset proposed by the American code was found. The tested results showed that the yielding strength perpendicular to grain of PSB was stable, the variable coefficient was between 5.88% and 13.34%, and the average yielding strength values were 80.84 MPa, 77.40 MPa, 76.52 MPa, 74.20 MPa, and 67.01 MPa, respectively, which decreased with the increase of bolt diameter, and the average yielding strength values are larger than the calculated results using theoretical formula. Therefore, the theoretical equation on embedding yielding strength of wood in the American code and European code applies to PSB.

Connection is an important part of the bamboo and timber structure, and it directly influences the overall structural performance and safety. Based on a comprehensive analysis of the mechanical performance of several wood connections, a new connector for the bamboo (timber) frame joint was proposed in this paper. Three full‐scale T‐type joint specimens were designed to study the mechanical performance under cyclic loading. The thickness of the hollow steel column was different among three specimens. The specimens were loaded under displacement control with a rate of 10 mm per minute until the specimens reach failure. It was observed that the failures of three specimens were caused by the buckling of flanges in the compression and that the steel of connections does not yield. The load‐displacement hysteretic curve for three specimens is relatively plump, and the stiffness of connection degenerates with the increasing of cyclic load. The maximum rotation is 0.049 rad, and the energy dissipation coefficient is 1.77. The thickness of the hollow steel column of the connector has significant impact on the energy dissipation capacity and the strength of the connection. A simplified moment‐rotation hysteresis model for the joint was proposed.

Laminated bamboo (LB), as a novel eco-friendly composite material with a high strength-to-weight ratio, has garnered increasing interest. However, there is a gap in comprehending the impact of size on the tensile properties of LB, particularly tensile strength and modulus. In contrast with conventional materials such as concrete and wood, which have specified specimen sizes and size effect factors to address performance variances linked to size, LB lacks such standards and references. To address this, seven groups of LB specimens of varying sizes were developed and tested to examine the impact of length, thickness, and sectional area on failure mechanisms and fundamental features, including density considerations. The findings demonstrate that size does not significantly influence the failure mode. Length exerts a smaller influence than thickness. When specimens are scaled up by a factor of two, tensile strength and modulus diminish to 82.86% and 88.38% of their initial values, respectively. Density significantly influences the relationships of tensile strength, modulus, and size effects. Consequently, size effect models incorporating both specific properties and the density–property relationship were developed.

Laminated bamboo (LB) represents a promising sustainable construction material, inheriting bamboo’s high strength, lightweight properties, and good ductility. However, the dimensional stability of mechanical performance—specifically size effects—remains a critical design challenge requiring systematic investigation. This study investigates the compression behavior of LB with tests of four specimen groups spanning volumes from 62,500 to 4,000,000 mm³ (25 × 25 × 100 mm to 100 × 100 × 400 mm). The research objectives encompass (i) characterizing compression behavior and failure mechanisms across different specimen scales, (ii) quantifying geometric and volumetric size effects on mechanical properties, (iii) evaluating theoretical frameworks for size effect prediction, (iv) developing progressive modeling approaches incorporating material heterogeneity, and (v) establishing design parameters for practical applications. Results demonstrate modest proportional size effects (1.60% strength reduction, 8.62% modulus reduction for 4× proportional scaling) but significant geometric optimization benefits, with cubic specimens achieving 15.78% higher strength and 25.11% greater modulus than equivalent-volume prismatic specimens. All specimens exhibited interfacial delamination failure with size-dependent crack propagation patterns. Theoretical analysis incorporates Weibull statistics, Bažant’s fracture mechanics, and Carpinteri’s fractal theory, with fracture energy modeling performing optimally. Three progressive modeling approaches achieve prediction accuracies ranging from 1.17% to 0.37% errors, with density-coupled modeling providing superior performance despite minimal density variations (COV = 9.27%). The research establishes size effect factors (0.86 for strength, 0.78 for modulus) and critical dimensions (125.64–126.14 mm), addressing critical gaps in LB size-dependent behavior. These parameters enable the development of reliable design methodologies for large-scale sustainable construction.

Laminated bamboo (LB) has shown enough exceptional performance to be used in constructions, but the performance of the bolted connections remains to be explored. To meet the criteria of low-carbon construction and fill the research gap in LB dowel embedment performance, this study examined the longitudinal dowel embedment behavior of LB. Failure modes, load–displacement curves, embedment strength, and elastic foundation parameters were examined after four sets of half-hole specimens with dowel diameters (6, 8, 10, and 12 mm) were tested in accordance with ISO 10984-2. The majority of the data was confirmed to follow a normal distribution by the Kolmogorov–Smirnov test. Interlaminar shear failure (dominant in 10 and 12 mm groups) and local crushing (dominant in 6 and 8 mm groups) were the primary failure modes. There were clear linear and nonlinear phases in the load–displacement curves (excellent ductility). The average elastic foundation modulus was 3565.55 MPa (0.39 times the compressive modulus); meanwhile, the average proportional limit, yield, and ultimate strengths were 35.48, 63.08, and 74.44 MPa (0.59, 1.06, and 1.25 times the parallel-to-grain compressive strength). The ultimate strength varied from 72.64 MPa to 76.71 MPa as the diameter rose; however, the elastic foundation beam coefficient dropped significantly. A novel calculation based on LB’s parallel-to-grain compressive strength accorded well with test results, while the existing code formulae (GB 50005, NDS, and CSA O86) overestimated LB embedment strength. The design of LB bolted connections is guided by this study, which also explains LB embedment criteria and offers design parameters and a prediction method.