Muhammad Masood Rafi | NED University of Engineering and Technology (original) (raw)

Uploads

Papers by Muhammad Masood Rafi

Research Square (Research Square), Oct 13, 2023

The details of experimental testing of full-scale reinforced concrete (RC) columns are presented ... more The details of experimental testing of full-scale reinforced concrete (RC) columns are presented in this paper. These columns were reinforced with hot-rolled thermo-mechanically treated (TMT) bars with yield strength higher than recommended in the prevalent manufacturing standards. The parameters of the study were the concrete con nement and concrete core area which were investigated using three specimen columns having lap-spliced longitudinal bars at the base. Although the initial cracks in all the columns were similar, the severely damaged region shifted in the vicinity of the end of dowel bars in the column with lesser con nement due to rebar slip. This type of behaviour in uenced exural rigidity and curvature distribution for this specimen. The maximum lateral load capacity and ductility of the specimen with lesser con nement were also the lowest. On the contrary, the specimen with higher con nement and core concrete area exhibited the highest stiffness and load capacity.

Journal of Performance of Constructed Facilities, Aug 1, 2023

Fire and Materials

Evacuation models represent one of the main tools used to assess building fire safety. Existing e... more Evacuation models represent one of the main tools used to assess building fire safety. Existing evacuation models are based on data from evacuation drills in western and developed countries, while there is a need for data from South Asian and developing countries (in general). This paper presents the results of an evacuation drill carried out in a library of a developing country in South Asia (Pakistan). The data of 85 student evacuees were recorded and analysed. Pre‐evacuation and walking speed data have been reported in this paper which are compared with the available data for library evacuations in other countries. The average pre‐evacuation time of 24.3 s (± standard deviation [SD] = 19.83 s) obtained in this study was shorter than previously published data for similar building types in other parts of the world. Furthermore, unimpeded horizontal speeds (mean = 0.74 m/s, SD = 0.28 m/s) were also smaller than the values reported in the available literature. Stair descending speeds...

Journal of Performance of Constructed Facilities

Response of Structures Under Extreme Loading (PROTECT 2015), 2015

International Journal of Masonry Research and Innovation, 2021

Proceedings of the Institution of Civil Engineers - Structures and Buildings, 2018

The results of shaking table tests of a one-third stone masonry building model have been presente... more The results of shaking table tests of a one-third stone masonry building model have been presented in this paper. The model was subjected to four levels of acceleration–time history record of the 1940 El Centro earthquake. These levels include 75% (R75), 100% (R100), 125% (R125) and 150% (R150). The data relating to acceleration and displacement were recorded and analysed. The fundamental mode of vibration of the structure was observed at all the levels of ground acceleration that were employed. The in-plane walls at the first storey were severely damaged as the structure was subjected to the increasing levels of peak ground acceleration. The maximum structure response to the ground vibration was observed at the R100 level of acceleration–time history. The fundamental frequency of the model decreased from 9/s for the virgin structure to 1/s after the R150 test run, whereas the damping ratio increased from 4·88 to 29·77%. The idealised resistance curve of the tested model indicated a...

Online Information Review, 2018

PurposeDisaster management information systems (DMISs) have been proposed in different parts of t... more PurposeDisaster management information systems (DMISs) have been proposed in different parts of the world for effective response to a disaster. The purpose of this paper is to: compare design approaches of these DMISs; examine similarities in the design of databases and communication infrastructure; and draw conclusions. Based on the examination of the studies, future opportunities have been identified and discussed.Design/methodology/approachThe studies in the available literature on the designs of automated DMISs have been reviewed in the presented paper to identify similarities in design premise, conceptual design and design considerations.FindingsThe examination of the available studies indicates that the research on DMIS has increased significantly in different countries of the world since 2004. Data of baseline information and available resources are required by most of the presented studies, as these data are necessary for effective response to a disaster. The communication i...

Proceedings of the Institution of Civil Engineers - Construction Materials, 2019

This paper presents the results of experimental testing at elevated temperatures of two types of ... more This paper presents the results of experimental testing at elevated temperatures of two types of steel rebars locally available in Pakistan. These include cold-drawn twisted (CDT) bars and hot-rolled thermo-mechanically treated (TMT) bars. Two rebar diameters (12 and 16 mm) of both types of bars were included in the testing programme. The bars were heat treated in an electrical furnace at 100−900°C in increments of 100°C. The yield strength of the 12 mm dia. hot-rolled TMT bar was less than the recommended strength of 500 MPa at ambient temperature. The yield phenomenon and strain hardening were not observed in the CDT bars either at ambient or high temperatures. The yield plateau of the hot-rolled TMT bars also disappeared after 300°C of heating. The ultimate strength of the hot-rolled TMT bars up to 300°C was higher than the strength at ambient temperature due to the precipitation of iron nitride in these bars (termed as blue brittleness effects). The reduction coefficients for yi...

Sustainable and Resilient Infrastructure, 2017

Adobe buildings exist all over the world as these are economically constructed with cheaper earth... more Adobe buildings exist all over the world as these are economically constructed with cheaper earthen materials. This paper compares the construction practices of adobe buildings in Pakistan with those in other parts of the world. The data of adobe material properties available in the literature have been reviewed and compiled. The observed failure modes of the adobe buildings in Pakistan from recent earthquakes are correlated with those that have been documented in the literature. A review of numerical studies on the seismic behaviour of adobe structures from different parts of the world is carried out and their limitations are identified.

Bulletin of Earthquake Engineering, 2017

This paper presents the results of shaking table tests of shear wall panels made of cob materials... more This paper presents the results of shaking table tests of shear wall panels made of cob materials. A proposed low-cost retrofit design was applied on one of the panels. The retrofitting was carried out with vertical bamboo sticks and horizontal layers of plastic coated steel wire mesh. A similar wall panel without retrofit was used as a control specimen. The wall panels were 1 m in height and length each with a thickness of 150 mm. The height and thickness were selected to simulate one-third model dimensions of the prototype walls employed in cob buildings in Balochistan, Pakistan. The walls were instrumented with accelerometer and string pots to measure acceleration and displacement, respectively. The decay in the dynamic characteristics of the retrofitted wall panel was less than the unretrofitted control wall panel. The displacement and acceleration of the unretrofitted control specimen increased drastically after a peak ground acceleration (PGA) of 1 g (0.33 g in the prototype domain). The acceleration response of the control specimen decreased at a PGA of 2.25 g (0.75 g in the prototype domain) and it failed by toe crushing at a PGA of 4.55 g (1.52 g in the prototype domain). No significant damage or change in the behaviour of the retrofitted wall panel was observed up to a PGA of 5.19 g (1.73 g in the prototype domain). The applied in-plane moment on the unretrofitted wall panel reached to a maximum value at a PGA of 1.23 g (0.41 g in the prototype domain) whereas the retrofitted wall was subjected to similar maximum moment at a PGA of 3.43 g (1.14 g in the prototype domain). The results clearly indicate that the proposed retrofit design is effective in improving the in-plane response of the cob shear wall and can be used for both the existing and new cob structures.

Proceedings of the Institution of Civil Engineers - Civil Engineering, 2017

This paper reports on a research-based initiative to improve the seismic resilience of the built ... more This paper reports on a research-based initiative to improve the seismic resilience of the built environment in a remote and impoverished town in Pakistan. Gajjar in Balochistan province was at the epicentre of two major earthquakes in September 2013, which resulted in the loss of 500 lives and nearly 20 000 properties. The strategy for reconstruction and rehabilitation of the town was based on scientific principles of town planning and seismic-resistant construction. The authors gathered damage data and proposed redevelopment plans for the area to the local authorities. Design of seismically retrofitted houses was carried out for private housing and training sessions were conducted to educate local people in the methods of safe construction. The aim is to contribute to the improvement of disaster resilience of the society.

Public Works Management & Policy, 2012

ABSTRACT

Building Pathology and Rehabilitation, 2013

Bulletin of Earthquake Engineering, 2014

This paper presents the record of damages which were observed in Pakistan due to a strong earthqu... more This paper presents the record of damages which were observed in Pakistan due to a strong earthquake on 16 April 2013 in Iran. Mashkel was the nearest town in Pakistan close to the epicentre of earthquake. The damages were documented by a survey team during the visit of Mashkel. The intensity of earthquake in most of the visited areas was found to be VIII on the Modified Mercalli Intensity scale. The infrastructure facilities were undamaged and were operating satisfactorily. On the other hand, heavy damage to adobe buildings was caused by the earthquake. Most of the building failure was resulted by the out-of-plane wall collapse; nearly 40 % adobe buildings were collapsed due to ground shaking in some of the affected areas. Reinforced concrete and cement concrete block masonry buildings performed better than adobe buildings. Using the data of building damage and earthquake intensity fragility curves for adobe buildings in Mashkel were developed.

Adobe buildings exist in different parts of the world. The construction of these buildings can be... more Adobe buildings exist in different parts of the world. The construction of these buildings can be carried out economically, using locally available materials and skills that do not require use of modern machinery. Therefore, adobe buildings provide an economic housing option. The construction of adobe structures is carried out based on traditional construction practices which vary from region to region. This paper presents the results of a study which was conducted to study the construction practices of adobe buildings in Pakistan and Portugal in the context of their seismic vulnerability. The adobe buildings in both these countries were found to be subjected to seismic hazard levels which, although is low in some regions, may cause significant damages. Lack of essential elements or details for the adequate seismic performance was found in the adobe buildings in both regions.

Strength of Materials, 2019

The results of analytical analysis of interfacial bond stress-slip behavior of steel bars embedde... more The results of analytical analysis of interfacial bond stress-slip behavior of steel bars embedded in recycled aggregate concrete (RAC) are reported in this paper. Significantly large data from the laboratory pullout tests of specimens were analyzed including the specimens tested by the author. A bond stress-slip constitutive law is proposed for the steel rebars embedded in RAC. The experimental stress-slip responses of specimens were compared with the theoretical predictions. An existing model in the literature was employed for determining the ascending branch of the bond stress-slip curve. Based on the differences in the observed and predicted responses, a modified expression to capture the descending branch of the bond stress-slip curve was proposed. The results of the modified expression correlated well with the observed data of samples tested by the author and those reported in the existing literature.

Journal of Composite Materials, Nov 1, 2007

A non-linear finite element model is presented for the analysis of simply supported reinforced co... more A non-linear finite element model is presented for the analysis of simply supported reinforced concrete beams. Cracked concrete is considered as an orthotropic material and the crack formation is simulated as smeared cracks. A rotating crack method is employed based on the total strain crack model. The analysis was carried out with the help of 2D isoparametric plane stress elements. Compression and tension softening and tension stiffening effects of the cracked concrete were considered. The tension reinforcement consisted of either steel or fiber reinforced polymer (FRP) bars. Excellent convergence and numerical stability of the formulation was found. The model showed good agreement with the recorded data of the tested beams.

Strength of Materials, Nov 1, 2018

Óíèâåðñèòåò èíaeåíåðèè è òåõíîëîãèè NED, Êàðà÷è, Ïàêèñòàí Ïåðåðàáîòêà áåòîíà ÿâëÿåòñÿ îäíèì èç ýô... more Óíèâåðñèòåò èíaeåíåðèè è òåõíîëîãèè NED, Êàðà÷è, Ïàêèñòàí Ïåðåðàáîòêà áåòîíà ÿâëÿåòñÿ îäíèì èç ýôôåêòèâíûõ ðåøåíèé ïðîáëåìû óòèëèçàöèè ñòðîèòåëüíûõ îòõîäîâ. Èññëåäóåòñÿ èçìåíåíèå àäãåçèîííûõ íàïðÿaeåíèé íà ñòûêå ñòàëüíûõ àðìàòóðíûõ ñòåðaeíåé ñ ìàòðèöåé èç ïåðåðàáîòàííîãî áåòîíà â çàâèñèìîñòè îò âåëè÷èíû ïðîñêàëüçûâàíèÿ ìåaeäó íèìè. Àäãåçèîííûå èñïûòàíèÿ íà ðàñòÿaeåíèå ïðîâîäèëèñü íà êîíöåíò-ðè÷åñêèõ îáðàçöàõ. Îáðàçöû ñ íàïîëíèòåëåì èç ñòàíäàðòíîãî áåòîíà èñïîëüçîâàëèñü â êà÷åñòâå êîíòðîëüíûõ. Èññëåäîâàëèñü àðìàòóðíûå ñòåðaeíè äâóõ òèïîâ (ãîðÿ÷åêàòàíûå äåôîðìèðîâàííûå è õîëîäíîêðó÷åííûå ðåáðèñòûå) ñ ðàçíûìè äèàìåòðàìè è ðàçíîé äîëåé äîáàâêè ïåðåðàáîòàííîãî áåòîíà. Äëèíà çàäåëêè ñòåðaeíåé ïÿòèêðàòíî ïðåâûøàëà èõ äèàìåòð. Ñòåðaeíè äèàìåòðîì 12 ìì èìåëè íàèâûñøóþ ïðî÷íîñòü ìåaeôàçíîãî ñöåïëåíèÿ/ àäãåçèè, êîòîðàÿ óìåíüøàëàñü ñ óâåëè÷åíèåì èõ äèàìåòðà. Âåëè÷èíà äîëè äîáàâêè ïåðåðàáîòàííîãî áåòîíà ïðàêòè÷åñêè íå âëèÿëà íà àäãåçèîííóþ ïðî÷íîñòü ñòåðaeíåé. Ïðè ýòîì ðåàêöèÿ õîëîäíîêðó÷åííûõ ðåáðèñòûõ ñòåðaeíåé ïî äîñòèaeåíèè ïèêà àäãåçèîííûõ íàïðÿaeåíèé â çàâèñèìîñòè îò ïðîñêàëüçûâàíèÿ îêàçàëàñü áîëåå aeåñòêîé, ÷åì ãîðÿ÷åêàòàíûõ äåôîðìèðîâàííûõ ñòåðaeíåé.