Connections between precast concrete elements play a crucial role in ensuring structural integrity and facilitating effective force transfer. Among various connection types, the column–foundation connection is the most critical component, as it is designed to resist the combined effects of axial load, bending moment, and shear force. In this study, the pocket connection was modified with anchored reinforcement (BPC) to improve seismic performance. An experimental program was conducted on three specimens: a monolithic cast-in-place connection (MC) as the control, a conventional pocket connection (PC), and the modified pocket connection (BPC). Each specimen was subjected to combined axial and cyclic loading to evaluate the seismic performance of the column–foundation connection. The results showed that the MC specimen demonstrated the best performance, while the PC specimen, although meeting the ACI 374.1-05 acceptance criteria, failed to achieve the required probable moment capacity. The BPC specimen demonstrated improvement in seismic performance compared to the PC and was considered suitable for use in precast structural systems designed for seismic area.
Various alternative, enhanced finite element methods (FEMs) have been proposed to improve the accuracy and convergence of traditional FEM. One promising approach is the hybrid FEM-meshfree method using the partition of unity concept. This study examines the performance of two variants of the hybrid-meshfree method: the three-node triangular element with continuous nodal stress (T3-CNS) and the three-node triangular element with discontinuous nodal stress (T3-DNS). These methods are evaluated in the context of surface fitting through numerical tests. Their accuracy and convergence are compared with the standard triangular element and Kriging-based FEM. The results show that both T3-CNS and T3-DNS methods maintain consistency and yield accurate surface approximations with good convergence. However, their performance declines in problems involving gradient singularities. This study enhances the understanding of T3-CNS and T3-DNS interpolations, providing insights into their application in a Galerkin method for solving engineering model problems.
This study examined the performance of limestone calcined clay cement (LC3) produced with Indonesian clays containing low–medium kaolinite (20–30%) and clinker contents below 50%. Material characterization was carried out using XRF, XRD, and particle size analysis, followed by evaluation of fresh and mechanical properties. LC3 mixtures incorporating local clays exhibited good workability and required less superplasticizer than metakaolin-based controls, indicating favourable fresh behaviour despite reduced clinker content. A notable strength reduction was observed when clinker content dropped below 35%, reflecting insufficient portlandite required for pozzolanic reactions. The addition or substitution of Ca(OH)₂ did not improve strength and hindered calcined clay reactivity due to elevated pH level (12.5–13.5). Microstructural analysis confirmed that mixtures with higher kaolinite and clinker contents produced denser hydration products. The results demonstrated that Indonesian clays are suitable for LC3 development, with promising fresh properties and microstructural behaviour supporting further optimization and future durability studies.
Cold bonded lightweight aggregate generated from fly ash (FA LWA) has become an interesting approach to increase the consumption of fly ash and prevent over-mining of natural aggregate. However, using the cold-bonded hardening method could increase the number of open pores in LWA, making the concrete containing this LWA face an increased risk of degradation due to water ingress. Thus, in this research, the effect of using FA LWA in concrete on the mechanical and transport properties in a salt environment is being investigated. Three aggregate replacement ratios of 0, 50, and 100% were applied, while the salt environment was mimicked with NaCl and Na2SO4 solutions. The results show that the optimum replacement rate of FA LWA was 50%. Regarding the transport properties, exposing concrete to a salt environment (NaCl or Na2SO4) proved to slow down the capillary imbibition rate slightly.
Current understanding of students’ mobility patterns often overlooks the integration of perceptual experiences with spatial behavior, particularly in rapidly urbanizing Global South contexts where informal infrastructures and cognitive factors critically shape mobility. This study addresses this gap by analyzing route preference determinants at Politeknik Negeri Ujung Pandang using mental map sketches (n=165), questionnaires, and GIS-based spatial analysis. Key findings reveal: 1) dense morning commutes within 500m of campus versus afternoon dispersal into alternative routes up to 2km; 2) distance (r = 0.876, p < 0.01) and travel time (r = 0.699, p < 0.01) dominate choices, outweighing convenience (r = 0.196, p < 0.05); and 3) gendered behaviors, with 65% of alternative route users were males. The findings validate Hägerstrand’s Time-Geography model and recommend arterial corridor optimization and safety retrofits, advancing an equitable framework for campus mobility planning.
