Seismic Retrofit of Reinforced Concrete Shear Walls using Fibre Reinforced Polymer Composites

In the past few decades, there have been considerable advancements in the design of reinforced concrete (RC) shear walls for new construction, such as performance-based seismic design and capacity design principles. These advancements have resulted in a concurrent need for upgrading the seismic performance of existing RC shear walls so that they can meet the safety requirements of modern seismic design codes. As such, there is a need to retrofit existing RC structural shear walls to increase their capacity at locations of higher seismic demands. These upgrades could be at the plastic hinge zone at the base of a wall, or at higher stories due to the effects of higher modes of vibration. This research aims to evaluate the effectiveness of using externally bonded carbon fibre-reinforced polymers (CFRP) in the seismic retrofit of RC shear walls. The research program comprises three phases. First, the testing of two 8-storey RC shear walls rehabilitated using CFRP composites under dynamic excitation. The walls were designed according to the NBCC 2005 and the CSA-A23.3-04. The walls were first tested under a simulated earthquake excitation using the shake table at the École Polytechnique de Montréal, where they experienced higher demands and nonlinearity at the sixth storey panel due to the effect of higher modes of vibrations. The tested walls were rehabilitated at the ground and at the sixth-storey level and retested on the shake table when subjected to several levels of ground motion excitation. In the second phase, three RC shear wall iv panels were tested under cyclic lateral excitation at the Structures Laboratory of Concordia University. The tested wall panels represent the control wall and two FRP-retrofitted panels using two different retrofit schemes. All three wall panels had reinforcement details similar to those of the sixth-storey panel of the code-designed 8-storey shear walls from the first phase. The walls were tested when subjected to a constant axial load along with synchronized cyclic moment and shear force at the top of the tested panel. The main purpose of the FRP-retrofit schemes was to increase the flexural and shear capacities of the tested wall panels and to assess the effectiveness of the FRP-retrofit schemes up to failure. In the third phase, a numerical macro-model was proposed to simulate the behaviour of the control and the retrofitted wall panels tested under cyclic loading. The experimental test results of the FRP-retrofit schemes used in the two 8-storey RC shear walls and the three RC wall panels showed a satisfactory performance with improved flexural strength; the testing showed that the main retrofit objectives were achieved. The nonlinear numerical macro-model was able to simulate the monotonic and cyclic behaviour of the wall panels tested under cyclic loading

Analytical study on upgrading the seismic performance of nominally ductile RC frame structures using different rehabilitation techniques

There exist many reinforced concrete (RC) buildings that are located in seismically active zones and designed according to older strength-based codes. These buildings are susceptible to abrupt non-ductile strength deterioration once their ultimate strength is reached, which reduces the energy dissipation capacity of those buildings and results in a brittle failure. Therefore, enhancing the seismic performance of such structures is essential and should not be overlooked. Recently, performance-based seismic design methodology is being adopted by several codes, in which seismic performance is described by designating the maximum allowable damage state index for an identified seismic hazard level. Overall lateral deflection, ductility demand, and inter-storey drift are the most commonly used damage state indices. The objective of this study is to analytically investigate the effectiveness of different rehabilitation patterns in upgrading the seismic performance of existing non-ductile RC frame structures. The study investigates the performance of three RC frames (with different heights) with or without masonry infill when rehabilitated and subjected to three types of ground motion records. The heights of the RC frames represent low, medium and high-rise buildings. The ground motion records represent earthquakes with low, medium and high frequency contents. Three models were considered for the RC frames; bare frame, masonry-infilled frame with soft infill, and masonry-infilled frame with stiff infill. The studied rehabilitation patterns include (1) introducing a RC shear wall, (2) using steel bracing, (3) using diagonal FRP strips (FRP bracings) in case of masonry-infilled frames, and (4) wrapping or partially wrapping the frame members (columns and beams) using FRP confinement. The seismic performance enhancement of the studied frames is evaluated in terms of the maximum applied peak ground acceleration or velocity resisted by the frames, maximum inter-storey drift ratio, maximum storey shear to weight ratio and energy dissipation capacity

Incidence of cervical stump metastasis after subtotal hysterectomy done to cases proved later by histopathology to be endometrial cancer in Al Shatby university maternity hospital patients

Background: Subtotal hysterectomy is associated with lesser complication, lesser time consuming than total one, but total hysterectomy has advantage of radicality of its management in cases of accidentally undiagnosed endometrial cancer proved later on by histopathology, that why hysterectomy should be total even in apparently benign causes that indicate it. The aim of this study was to access incidence of cervical stump invasion by malignancy in endometrial cancer cases and its relation to pathological types after subtotal hysterectomy done to cases proved later by histopathology to be endometrial cancer.Methods: Following approval by our institutional ethics committee a prospective and retrospective observational descriptive study was done on 100 patients recruited from gyne-oncological outpatient clinic of Shatby university hospital of Alexandria from August 2018 to June 2021 with past history of subtotal hysterectomy. All these cases were proved later after histopathological examination of the uterine body to have type 1 or type 2 endometrial cancer. Stumpectomy was done to all patients after a written informed consent were taken from them before the study. Histopathological examinations of the cervical stumps were done and incidence of stump invasion with cancer in relation to its type was analyzed.Results: Histopathological examination of the stump of all cases revealed that only 13 cases showed microscopic stump invasion. 7 cases with stump invasion were type 1 endometrial cancer, 4 cases were grade 1 and 3 cases were grade 2 in relation to 6 cases of stump invasion were type 2 endometrial cancer with papillary serous adenocarcinoma. Regarding relation between stump invasion and pathological types of endometrial cancer there was a significant statistical difference between them as type 2 are associated by higher number of stump invasion (p=0.0001).Conclusions: The present study concluded that cases subjected to subtotal hysterectomy with undiagnosed endometrial cancer are associated with considerable incidence of cervical stump invasion and type 2 endometrial cancer have higher incidence of cervical stump invasion in relation to type 1 endometrial cancer

Comparison between Pap smear and visual inspection with acetic acid in screening of premalignant cervical intraepithelial lesion and subclinical early cancer cervix

Background: The objective of the study was to compare the sensitivity, specificity, positive predictive value and negative predictive value of VIA and Pap smear in screening of premalignant cervical intraepithelial lesion and subclinical early cancer cervix.Methods: An observational prospective study was done for 350 patients attending the gynecology outpatient clinic of the shatby maternity university hospital for any reasons, VIA and Pap test were done for all patients, then colposcopic guided biopsy from cases with positive colposcopic findings. Histopathological examination was done for collected biopsy. Collected data was statistically analyzed to compare between both tests (PAP and VIA).Results: Our results showed that the sensitivity of PAP test was 83.3%, specificity was 90.7%, positive predictive value was 50.8%, negative predictive value was 97.9% and accuracy was 90% while the VIA test had a sensitivity of 66.7%, specificity was 91%, positive predictive value was 46.1%, negative predictive value was 95.9% and accuracy was 88.5%.Conclusions: Via test has comparable results to Pap test regarding its sensitivity, specificity, positive predictive value, negative predictive value and accuracy and can be used as an alternative primary test to screen premalignant cervical intraepithelial lesion and subclinical early cancer cervix

The efficacy of ultrasonographic morphological index using Depriest score in ovarian cancer prediction

Background: Ovarian cancer is the second most common cancer after cancer breast and the most lethal gynecologic malignancy in developed countries.The objective of this study was to evaluate the efficacy of ultrasonographic morphological index using Depriest score et al in identifying ovarian cancer and to calculate its specificity, sensitivity, positive predictive value and negative predictive value in ovarian cancer prediction.Methods: Preoperative estimation of morphological index by Depriest score using vaginal ultrasound examination for 130 cases with ovarian masses, followed by laparotomy, and histopathological examination of the masses. Correlation of the cases morphological index score was done for histopathological nature of masses whether it is benign or malignant. Calculation of the Depriest index score was done using 3 parameters which are tumor volume, cyst wall structure and thickness and Septal structure.Results: A significant difference were found between mean Depriest score (p=0.001) of malignant cases (mean score 8.27±1.77) and benign cases (mean score 4.38±1.61) while the mean volume showed no significant difference (p=0.101) between malignant (mean volume 3.24±0.69) and benign cases (mean volume 3.00±0.91). In relation to CA125 there was a significant difference (p=0.001) between malignant (mean CA125 86.34±73.87) and benign cases (mean CA125 31.48±12.83).Conclusions: Depriest et al morphological index is an effective and cost efficient method for malignant ovarian masses prediction and differentiation from benign masses

Comparison of risk of malignancy indices in the preoperative evaluation of adnexal masses

Background: An adnexal mass patient is a common cause of hospital admission. The differentiation between malignant and benign cases is an important step in the management of such patients. The risk of malignancy index (RMI) is a simple scoring system depend on ultrasound data, menopausal status and serum concentrations of CA-125 tumor marker and has a great value in differentiation between benign and malignant adnexal masses. 4 different types of risk of malignancy index are created. The objective of the study was to compare the diagnostic performance of the four malignancy risk indices in differentiating benign and malignant ovarian tumors.Methods: This prospective study was performed on 60 patients with an adnexal mass confirmed on vaginal ultrasound.Results: There was statistical significance difference between the 4 types of RMI in benign and malignant groups. RMI 1, RMI 2, and RMI 3 had nearly the same area under the ROC curve; however, at the cut-off of>58.41, RMI 3 was more sensitive and less specific than RMI 1 or RMI 2. The RMI 2 was the most specific in predicting malignancy in terms of area under the curve; however, there was no statistically significant difference in performance of RMI 2 and 4 in malignant group.Conclusions: RMI 1, RMI 2, and RMI 3 had nearly the same area under the ROC curve; however, at the cut-off of >58.41, RMI 3 was more sensitive and less specific than RMI 1 or RMI 2, on the other hand the most specific was RMI 2 more than the other 3 RMIs

Study of leucine-rich alpha-2-glycoprotein-1 marker serum level in cases of malignant epithelial ovarian tumors

Background: The aim of this study was to compare the level of LRG1 in epithelial ovarian cancer (EOC) cases with benign ovarian masses and to evaluate results in relation to CA125.Methods: An observational prospective controlled study was done on 70 patients admitted to El Shatby Maternity University Hospital, Oncology department categorized as follows: study group (group I) included 35 patients, with epithelial ovarian malignancy confirmed by histopathological examination and control group (group Il) included 35 patients with benign ovarian tumors confirmed by histopathological examination. Determination of Serum LRGI level by using enzyme-linked immuno sorbent assay with CA125 tumor marker analysis were done for all cases of both groups.Results: As regard comparison between the two studied groups according to CA125 and LRGI. CA125 in group I ranged from 14.90 to 4600 with a mean value 856.73±1104.03, in group II ranged from 7.45 to 523 with a mean value of 51.97±86.14. LRGI in group I ranged from 62.46 to 653.98 with a mean value of 130.86±119.78, in group Il ranged from 47.73 to 261.78 with a mean value of 77.35±38.75. There was statistically significant difference between the two studied groups regarding CA125 and LRGI (p≤0.05).Conclusions: LRG1 can be used as promising tumor marker to diagnose epithelial malignant ovarian cancer with or without CA125 tumor marker as it was significantly higher in epithelial ovarian cancer patients

The relation between of insulin like growth factor II and endometrial carcinoma

Background: Endometrial cancer is the most common gynecologic malignancy in the United States and the fourth most common cancer in women. The need of a soft marker that can be used with CA-125 tumor marker for early detection of endometrial cancer and to predict late stages and advanced histopathological grades and to specify the cases who will be managed by complete surgical staging including para aortic and pelvic lymphadenectomy is of great importance. The aim of the study was to evaluate the role of insulin like growth factor 2 in endometrial carcinoma and to correlate it with different histopathological grades of the disease.Methods: This study was applied on sixty patients with abnormal uterine bleeding and were divided into two groups, Group A included 30 cases of endometrial carcinoma, while Group B included 30 cases complaining of abnormal vaginal bleeding due to other causes as a control group. Serum samples were taken from all patients and estimation of IGF-2 serum levels using ElISA technique was done. Comparison of IGF-2 serum level between both groups and correlation of its levels with different histopathological grades of endometrial cancer group were done.Results: As regard comparison between both groups and ILGF2 serum level, study results demonstrated that ILGF2 levels ranged between 600.0-1440.0 ng/ml and 40.0-560.0 ng/ml with the mean of 781.33 ng/ml±196.45 and 336.0 ng/ml±212.86 for cases Group A and control Group B respectively. There was a statistically significant difference between the two studied groups regarding ILGF2 serum level (p<0.001). As regards correlation between histopathological grades and ILGF-2 serum level in cases Group A, the study revealed a strong positive correlation.Conclusions: ILGF-2 can be used as a serum marker for endometroid adenocarcinoma of the body of the uterus and to predict its higher histopathological grades