Sustainable Structures and Materials, An International Journal

Probabilistic Analysis of Strength of Structural Concrete for Post-Code Buildings in Developing Countries

2023-07-16T22:36:08-04:00

Code compliance and quality construction remain a point of interest for developing countries. For structural vulnerability studies on reinforced concrete buildings, researchers usually adopt random strength parameters to represent the compressive strength of concrete for various structural members. This matter becomes a challenge if researchers are dealing to quantify the structural response of code-compliant buildings. Since the research on the response of code-compliant buildings is limited hence this paper aims at data collection and presenting the probabilistic trends in compressive strength variation of structural concrete being used or has been used in multiple projects of the federal capital city of Pakistan for code-compliant buildings. The data has been collected from well-reputed academic and commercial testing labs in the area for past 10 years (the timeline after implementation of BCP 2007). Compressive strength testing records of concrete cylinders for 28 days strength have been sorted for different structural members i.e., beams, columns, shear walls, slabs and footings separately. From the selected data, histograms have been plotted for each member category and mean values with standard deviations have been highlighted. Obtained results are further compared with anticipated design compressive strengths which were obtained from different tagged reports, design offices and resident engineers of the sites. The produced results would lead to true representation of structural strength of concrete for code-compliant buildings, to be further studied for structural vulnerability and risk assessments of the desired areas in developing countries.

An experimental study on axial behaviour of recycled plastic aggregate concrete columns

2023-07-16T23:07:50-04:00

Plastic production and the resultant plastic waste is increasingly challenging due to population growth and urbanization. This study focuses on plastic reuse as an aggregate in concrete to explore the recycling avenue in the construction industry. In addition, the work focused on the mechanical properties of eco-friendly concrete that uses plastic waste as a partial substitution for coarse aggregate. From this method the negative impact of plastic waste on the environment not only reduced, but it also helps avoid exploitation of natural resources for natural aggregate production. Several past works have explored the use of plastic as an aggregate in concrete; however, most works were focussed on the material level behavior. In this study, compressive behaviour of reinforced concrete columns consisting of recycled plastic aggregate concrete and exposed to axial loads is investigated. This paper provides the axial loading test results of 5 columns consisting of Recycled Plastic Aggregate Concrete (RPAC). The replacement rate in the M40 grade concrete is kept at 12%. Compressive performance of RPAC columns such as strain, failure mode, reinforcement along longitudinal direction and ties spacing are analysed. The results clearly show the potential of recycled plastic aggregates for use in columns with structural performance equivalent to that of conventional aggregate concrete.

Study of Debris Flow Impact on Bridge Pier

2023-07-16T23:27:24-04:00

The destructive nature of debris has ability to transport large boulders and wooden material along with the flow whose impact can pose serious safety risks to a bridge. In this study an effort has been made to study the impact of varying debris densities on a bridge pier. The experimentation was carried out in Hydraulics Laboratory, Civil Engineering Department, University of Engineering and Technology Taxila. Hexagonal wooden pier model was used. Wooden sticks of uniform size and mass were used to act as debris in flow. Respective discharges were determined against different flow velocities. Dial gauge was installed carefully beside the bridge pier in a way that deflections were easily measurable. This debris of masses 189, 253, 316, 379 and 442 grams was floated on water for five trials at discharges of 10.3, 12.8, 16, 23.8 and 28.9 liters per second. Debris hit the pier and caused a deflection in it. These deflections were measured by a dial gauge. The results show that with increasing debris mass and intensity of flow velocity, the impact on the pier bridge in term of deflection increased. A hydraulic structure's health can be monitored using the findings of the current study.

Experimental Study on Seismic Response Characteristics of Soil On Building Models Using 1-D Shake-Table.docx

2023-08-14T02:28:41-04:00

ABSTRACT. This research investigates the impact of seismic response on the scaled 1:10 multi storey steel frame-model supported by isolated shallow footings placed on sand sample. One dimensional shake-table testing was carried out on four, three and two storeys steel Frame Model subjected to El-Centro 0.46pga Earthquake. Dynamic properties acceleration, displacement, natural frequency of the frame models on isolated footing with changing of storey height were measured. Moreover, it was found that acceleration responses and natural frequencies decreased with an increase in frame model height while displacement responses increased for a given foundation type with increased height. In conclusion, soil, the structure's height, and the materials properties all affect a structures seismic response during an earthquake.