Experimental Behavior of Full Scale URM Building Retrofitted with Ferrocement Overlay

2011 ◽  
Vol 255-260 ◽  
pp. 319-323 ◽  
Author(s):  
Mohammad Ashraf ◽  
Akhtar Naeem Khan ◽  
Qaisar Ali ◽  
Khan Shahzada ◽  
Amjad Naseer

This paper presents a study on the behavior of a damaged full scale unreinforced brick masonry building, retrofitted with ferrocement overlay and cement based grout injection, tested under cyclic loading. Damage mechanism and force-deformation behavior of the retrofitted structure are compared with its pre-damaged response to quantify the beneficial effects of retrofitting scheme. The lateral load capacity of the retrofitted building was significantly improved and the damage mechanism was transformed from mixed compression-flexural-shear mode to a more stable flexural rocking mode. The energy dissipation capacity, however, remained unchanged and the deformation capacity was slightly decreased.

Author(s):  
Yuka MATSUMOTO ◽  
Satoshi YAMADA ◽  
Ken OKADA ◽  
Masatoshi IDE ◽  
Toru TAKEUCHI ◽  
...  

2017 ◽  
Vol 27 (9) ◽  
pp. 1416-1447 ◽  
Author(s):  
Liu Jin ◽  
Shuai Zhang ◽  
Dong Li ◽  
Haibin Xu ◽  
Xiuli Du ◽  
...  

The results of an experimental program on eight short reinforced concrete columns having different structural sizes and axial compression ratios subjected to monotonic/cyclic lateral loading were reported. A 3D mesoscopic simulation method for the analysis of mechanical properties of reinforced concrete members was established, and then it was utilized as an important supplement and extension of the traditional experimental method. Lots of numerical trials, based on the restricted experimental results and the proposed 3D mesoscopic simulation method, were carried out to sufficiently evaluate the seismic performances of short reinforced concrete columns with different structural sizes and axial compression ratios. The test results indicate that (1) the failure pattern of reinforced concrete columns can be significantly affected by the shear-span ratio; (2) increasing the axial compression ratio could improve the load capacity of the reinforced concrete column, but the deformation capacity would be restricted and the failure mode would be more brittle, consequently the energy dissipation capacity could be deteriorated; and (3) the load capacity, the displacement ductility, and the energy dissipation capacity of the short reinforced concrete columns all exhibit clear size effect, namely, the size effect could significantly affect the seismic behavior of reinforced concrete columns.


2022 ◽  
pp. 136943322110572
Author(s):  
Xun Chong ◽  
Pu Huo ◽  
Linlin Xie ◽  
Qing Jiang ◽  
Linbing Hou ◽  
...  

A new connection measure between the precast concrete (PC) cladding panel and PC frame structure is proposed to realize a new kind of isostatic frame-cladding system. Three full-scale PC wall-frame substructures were tested under the quasi-static load. These substructures included a bare wall-frame specimen, a specimen with a cladding panel that has no opening, and a specimen with a cladding panel that has an opening in it. The damage evolution, failure mode, load-bearing capacity, deformation capacity, and energy dissipation capacity of three specimens were compared. The results indicated that the motions of the cladding panels and the main structures were uncoupled through the relative clearance of the bottom connections, and three specimens exhibited approximately identical failure modes and seismic performance. Thus, the reliability of this new isostatic system was validated.


2015 ◽  
Vol 9 (1) ◽  
pp. 295-307 ◽  
Author(s):  
Edelis del V. Marquez A. ◽  
William Lobo-Q ◽  
Juan C. Vielma

A comparative study has been done to analyze the behavior of regular steel building structures of 4, 6, 8 and 10 stories, located in seismic zone 5 and soil type S1. The structures were upgraded with different brace configurations according to current Venezuelan codes. A total number of 24 numerical models were analyzed considering non-linear static and incremental dynamic analysis (IDA). The buildings were initially designed as moment resisting frames, and upgraded with six different bracing configurations: concentric braces in “X” and inverted “V”; eccentric braces inverted "V" with horizontal links, inverted “Y” and “X” with vertical links. Short length links were used to ensure a shear failure. The used methodology is based on obtaining the capacity, IDA curves, and bilinear approximations of these curves that allow the determination of yield and ultimate capacity points, in order to estimate important parameters of seismic response: overstrength and ductility; and considering these areas under the curves to estimate elastic deformation energy, energy dissipated by hysteretic damping and equivalent damping. According to the results, the cases with no brace enhancement showed the lowest lateral strength and lateral stiffness and high deformation capacity. On the other hand, the concentric bracing cases, resulted with the highest stiffness and strength and the lowest deformation capacity, therefore they have low ductility and energy dissipation capacity under seismic loading. Structures with links showed intermediate stiffness and strengths, resulting in the best performance in terms of ductility and energy dissipation capacity. The present study provides a better understanding of the benefits of eccentrically braced systems.


Author(s):  
Takaomi GOTO ◽  
Takahiro KOKURA ◽  
Hiroshi SHIMA ◽  
Katsunori HIRANO ◽  
Terukatsu SASAYA ◽  
...  

Author(s):  
Kyle M. Rollins ◽  
Andrew E. Sparks ◽  
Kris T. Peterson

Static and dynamic (statnamic) lateral load tests were performed on a full-scale 3 × 3 pile group driven in saturated low-plasticity silts and clays. The 324-mm outside diameter steel pipe piles were attached to a reinforced concrete pile cap (2.74 m square in plan and 1.21 m high), which created an essentially fixed-head end constraint. A gravel backfill was compacted in place on the back side of the cap. Lateral resistance was therefore provided by pile-soil-pile interaction as well as by base friction and passive pressure on the cap. In this case, passive resistance contributed about 40 percent of the measured static capacity. The measured resistance was compared with that computed by several techniques. The log-spiral method provided the best agreement with measured resistance. Estimates of passive pressure computed using the Rankine or GROUP p-y curve methods significantly underestimated the resistance, whereas the Coulomb method overestimated resistance. The wall movement required to fully mobilize passive resistance in the dense gravel backfill was approximately 0.06 times the wall height, which is in good agreement with design recommendations. The p-multipliers developed for the free-head pile group provided reasonable estimates of the pile-soil-pile resistance for the fixed-head pile group. Default p-multipliers in the program GROUP led to a 35 percent overestimate of pile capacity. Overall dynamic resistance was typically 100 to 125 percent higher than static; however, dynamic passive pressure resistance was over 200 percent higher than static.


2018 ◽  
Vol 1 (2) ◽  
pp. 1-12 ◽  
Author(s):  
Hafiz Muhammad Rashid ◽  
Shaukat Ali Khan ◽  
Rao Arsalan Khushnood ◽  
Junaid Ahmad

This article describes Dhajji Dewari which is a non-engineered traditional construction method mostly used in the northern parts of Pakistan. This method consists of a timber frame filled with the stones in a mud slurry. This article is aimed to assess the effects of different infills on the lateral load capacity of Dhajji Dewari. For this purpose, three full scale Dhajji Dewari panels were constructed and unidirectional in-plane lateral load was applied. One panel was without infill, two other panels with different type of infills. Results of the experimentation showed that the infill presence effects the lateral load resisting performance of the Dhajji Dewari.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3895
Author(s):  
Thomas Pidancier ◽  
Mokhtar Bozorg ◽  
Dominique Roggo ◽  
Patrick Favre-Perrod ◽  
Mauro Carpita

In this paper, a 15 kVA soft open point converter is presented. The converter design and manufacturing have been presented in previous papers. The aim of this paper was to show the results of the devices in a full-scale laboratory environment, Gridlab, made of four distribution LV feeders, each rated 40 A. The tests demonstrated the good dynamics of the SOP control and its usefulness in performing a suitable PQ control. They also showed an improvement in the voltage profile and in the load capacity of the overall network. In the final part of the paper, the feedback earned during the development and the test of this first prototype are presented. This feedback will benefit the team for the design of a new improved 50 kVA version.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2556
Author(s):  
Zheng-Ang Sui ◽  
Kun Dong ◽  
Jitong Jiang ◽  
Shutong Yang ◽  
Kexu Hu

In this paper, carbon fiber reinforced polymer (CFRP) and textile reinforced mortar (TRM) strengthening techniques were proposed to retrofit and strengthen fire-damaged prefabricated concrete hollow slabs. A total of six slabs, from an actual multi-story masonry building, were tested to investigate the flexural performance of reinforced concrete (RC) hollow slabs strengthened with TRM and CFRP. The investigated parameters included the strengthening method (CFRP versus TRM), the number of CFRP layers, and with or without fire exposure. One unstrengthened slab and one TRM strengthened slab served as the control specimens without fire exposure. The remaining four slabs were first exposed to ISO-834 standard fire for 1 h, and then three of them were strengthened with CFRP or TRM. Through the four-point bending tests at ambient temperature, the failure modes, load and deformation response were recorded and discussed. Both CFRP and TRM strengthening methods can significantly increase the cracking load and peak load of the fire-damaged hollow slabs, as well as the stiffness in the early stage. The prefabricated hollow slabs strengthened by CFRP have better performance in the ultimate bearing capacity, but the ductility reduced with the increase of CFRP layers. Meanwhile, the TRM strengthening technique is a suitable method for the performance improvement of fire-damaged hollow slabs, in terms of not only the load capacity, especially the cracking load, but also the flexural stiffness and deformation capacity.


2020 ◽  
Vol 23 (13) ◽  
pp. 2822-2834
Author(s):  
Xian Rong ◽  
Hongwei Yang ◽  
Jianxin Zhang

This article investigated the seismic performance of a new type of precast concrete beam-to-column joint with a steel connector for easy construction. Five interior beam-to-column joints, four precast concrete specimens, and one monolithic joint were tested under reversed cyclic loading. The main variables were the embedded H-beam length, web plate or stiffening rib usage, and concrete usage in the connection part. The load–displacement hysteresis curves were recorded during the test, and the behavior was investigated based on displacement ductility, deformability, skeleton curves, stiffness degradation, and energy dissipation capacity. The results showed that the proposed beam-to-column joint with the web plate in the steel connector exhibited satisfactory behavior in terms of ductility, load capacity, and energy dissipation capacity under reversed cyclic loading, and the performance was ductile because of the yielding of the web plate. Therefore, the proposed joint with the web plate could be used in high seismic regions. The proposed joint without the web plate exhibited similar behavior to the monolithic specimen, indicating that this joint could be used in low or moderate seismic zones. Furthermore, the utilization of the web plate was vital to the performance of this system.


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