Journal of Civil and Construction Engineering

Comparative Seismic Assessment of a G+10 Reinforced Concrete Building Using Equivalent Static and Response Spectrum Methods under ASCE/SEI 7-22

2026-10-19T10:55:55+00:00

This study compares the seismic response of a regular G+10 reinforced-concrete building using the equivalent-static and response-spectrum procedures in CSI ETABS 23.2.0. The building has a 24 m × 20 m plan, a 3.5 m first-storey height, 3.0 m typical storey height, and a total height of 33.5 m. The model uses 5000 psi concrete, ASTM A706 Grade 60 reinforcement, 150 mm floor slabs, and ACI 318-25 concrete-design settings recorded in the current ETABS export. Seismic response is examined in both principal directions using EQX and EQY for the equivalent-static cases and RSA X and RSA Y for the response-spectrum cases, within the ASCE/SEI 7-22 framework. The updated results give maximum displacements of 44.889 mm and 42.152 mm for EQX and EQY, compared with 40.947 mm and 35.810 mm for RSA X and RSA Y. The maximum storey drift ratios are 0.001764, 0.001622, 0.001629, and 0.001437, respectively. Global base reactions are 6363.18 kN and 6885.46 kN for the equivalent-static X and Y cases and 6326.72 and 6887.59 kN for the response-spectrum cases. The results therefore show close agreement in overall base reaction, while displacement and drift vary with both direction and analysis procedure. The study presents these results as a transparent numerical comparison and identifies the additional model and code checks required before the analysis can be used for final design decisions.

Barriers to Successful Completion of Urban Water Supply Projects: A Quantitative Performance Analysis of Nine UWSSP Subprojects in Western Nepal

2026-09-11T08:33:55+00:00

Urban water supply projects in Nepal frequently experience significant delays and cost overruns, yet systematic quantitative analysis of their performance remains limited. This study analyzes the quantitative performance of nine recently completed Urban Water Supply and Sanitation (Sector) Project (UWSSP) subprojects in Western Nepal, examining time overruns, extensions of time (EoT), Variation Orders (VO), and cost variance. Using project summary records from the Western Regional Project Management Office, the study found that all nine subprojects experienced universal time overruns ranging from 39.7% to 137.1% (average 69.0%), with eight of nine projects receiving three or more EoTs and seven of nine receiving two or more VOs. Counterintuitively, all projects were completed under budget relative to initial contract amounts, with cost variances ranging from -2.6% to -25.5% (average -12.4%). Tikapur Storm Water Drainage Project performed best on schedule (39.7% overrun), while Purnagiri WSS performed worst (137.1% overrun). The findings challenge conventional project management assumptions by demonstrating that severe schedule delays can coexist with apparent cost underruns. The study contributes empirical evidence on infrastructure project performance in Nepal's unique institutional context and provides baseline data for future comparative research.

Multi-Response Optimization of Mechanically Processed Recycled Aggregate for Concrete

2026-10-29T07:15:50+00:00

The engineering performance of recycled aggregate concrete is strongly controlled by the quality of the recycled aggregate and, in particular, by the quantity and condition of adhered mortar. This study develops a multi-response interpretation of an experimental high-strength concrete dataset in which recycled coarse aggregate was mechanically processed for 0, 200, 500, and 700 Los Angeles abrasion-machine revolutions and incorporated at 0–100% replacement of virgin coarse aggregate. The analysis combines workability, density, 28-day compressive strength, flexural strength, split tensile strength, ultrasonic pulse velocity, and elastic modulus to identify a practical processing–replacement window. The source experimental programme used a high-strength concrete mix with a water-to-cement ratio of 0.26, silica fume, and polycarboxylate-ether superplasticizer. The results show that increasing replacement generally reduces hardened performance, whereas increasing processing intensity improves performance by reducing adhered mortar and improving the effective aggregate–paste interface. At 50% replacement, the reported 28-day compressive strength increased from 46.78 MPa for unprocessed aggregate to 73.23 MPa after 500 revolutions, while the corresponding value at 700 revolutions was 75.42 MPa. Thus, the incremental strength gain from 700 over 500 revolutions was only about 3%, indicating a diminishing-return region. Similar convergence was observed for UPV and elastic modulus. A 500-revolution treatment therefore emerges as a practical compromise between performance and processing demand, while replacement around 50% provides a useful balance between recycled-material utilization and structural performance. The paper presents the performance map based on replacement level and processing intensity and identifies the experimental variables.

High-Performance Concrete with Treated Recycled Coarse Aggregate: A Performance-Gated Critical Review

2026-09-14T08:27:28+00:00

Recycled Coarse Aggregate (RCA) can reduce virgin aggregate demand and divert demolition waste. Still, its use in High-Performance Concrete (HPC) is constrained by adhered old mortar, source heterogeneity, high water absorption, microcracking, and multiple interfacial transition zones. This critical review synthesizes evidence on RCA quality, fresh behavior, mechanical response, transport-controlled durability, treatment technologies, and life-cycle performance using a strengthened structured-review protocol. The thesis-derived source set was updated and verified through 11 August 2026, yielding 22 core sources spanning RCA/HPC behavior, treatment and durability, life-cycle assessment, and governing standards. Experimental treatment evidence was used quantitatively only when treated and untreated RCA were compared at the same replacement level, or when the source reported a directly normalized change; incompatible mixture conditions and test methods were not statistically pooled. Reported effects demonstrate substantial but method-specific variability. Autogenous cleaning has reduced adhered mortar by about 50%, lowered water absorption by 20%–50%, and increased density by 3%–16%. Accelerated carbonation has produced a 22.6% increase in 28-day compressive strength in the cited pressure study, while cyclic carbonation studies report gains of about 25.2% in compressive strength and 26.5% in flexural strength. Nano-silica treatment has produced approximately 20%–25% compressive-strength gains, and optimized bio-mineralization has reduced aggregate water absorption by about 15%. These benefits are not universal: high-temperature removal can impose large energy burdens and has produced strength loss in some studies, while acid treatments may improve absorption and compression yet reduce flexural performance and create effluent. To translate the evidence into practice, the review operationalizes a non-compensatory performance-gated framework. Absolute project and code requirements take precedence; for the M60-class context, the 28-day characteristic compressive-strength requirement is at least 60 MPa. Where no codified limit exists, a provisional paired screening criterion of at least 0.90 retention for higher-is-better responses and no more than a 1.10 ratio for lower-is-better transport or damage indicators is proposed. Sustainability and cost is evaluated only after all mandatory technical gates pass.