Column-to-Beam Moment Capacity Ratio of Framed Building

Capacity design philosophy is the basis of behind the strong column weak beam concept for the improvement of earthquake resistant design.Damages at some in some pre-determined structural members may allowed in the earthquake-resistant design philosophy in order to have a good global behaviour of the building.In order to ensure a favorable failure mode,design codes recommend minimum value ofMoment Capacity Ratio(MCR)which is defined as the ratio of summation of column moment capacity to summation of beam moment capacity at a particular beam-column joint.During cyclic earthquake loading column experience a range of axial force due to various combinations of load,and unlike beam, column does not have a unique moment capacity.That makes the calculation of MCR cumbersome.There are discrepancies among the major international codes with regard to MCR.Indian standard codes for design of RC framed buildings are silent on this aspect.Draft 13920(2014)code suggests a value of MCR similar to other international codes without proper theoretical basis.Hence a rational study is required on the values of MCR.A computationally attractive procedure for calculating flexural capacity of column developed for determining MCR at a beam-column joint.To reach at an appropriate and acceptable MCR for capacity design of RC framed building reliability based approach is done.This research deals with the fragility and reliability analysis of four storey RC frames designed using various values of MCR ranging from 1.0 to 3.2. The RC frames are designed as per IS 1893(2002)for all seismic zones.Hazard curves required of various seismic location in India(like zone II, III, IV and V)has been selected from National Disaster Management Authority,Government of India. Seismic risk assessment of all the designed buildings is conducted and based on the achieved Reliability Index and the Target Reliability Index minimum value of MCR is suggested

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Path-Breakers: How Does Women's Political Participation Respond to Electoral Success?

This paper analyzes the effect of a woman's electoral victory on women's subsequent political participation. Using the regression discontinuity afforded by close elections between women and men in India's state elections, we find that a woman winning office leads to a large and significant increase in the share of female candidates from major political parties in the subsequent election. This stems mainly from an increased probability that previous women candidates contest again, an important margin in India where a substantial number of incumbents do not contest re-election. There is no significant entry of new female candidates, no change in female or male voter turnout and no spillover effects to neighboring areas. Further analysis points to a reduction in party bias against women candidates as the main mechanism driving the observed increase in women's candidacy

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

BACKGROUND: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. METHODS: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). FINDINGS: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29-146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0- 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25-1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39-1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65-1·60]; p=0·92). INTERPRETATION: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention. FUNDING: British Heart Foundation

Treatment of Recycled Coarse Aggregate as Sustainable Construction Material

Safe disposal of construction and demolition (C&D) waste is a major challenge globally. This study explores strengthening of recycled coarse aggregate (RCA) by conventional cement slurry and novel biocement treatment. Overall, the research contributes to the understanding insights of C&D waste issues, weakness of RCA and mitigation strategies, efficacy of treatment methods and benchmarking, and finally, possible disposal solutions by complete replacement of natural aggregate with treated RCA to achieve sustainability in the concrete industry

A review on different treatment methods for enhancing the properties of recycled aggregates for sustainable construction materials

With global increase in construction and demolition, recycling of construction debris as an aggregate can be a vital step towards achieving sustainability in concrete construction. However, a clear methodology for reuse of construction and demolition (C&D) waste in concrete is warranted for its use in practice. This paper reviews the challenges revealed hitherto such as weak interfacial transition zone, high water absorption and presence of micro cracks in the use of C&D wastes as the recycled aggregate (RA). Methods of mitigation of these weaknesses through various treatments have been reported. This review has a special focus on India, a country that generates one of the world's highest quantity of C&D waste. After analysing all the treatment methods, the authors summarize that the strengthening of attached mortar (AM) technique is better than removing of AM, which is also cost-effective, eco-friendly and sustainable. Use of nano-materials and pozzolana along with different mixing methods and application of bio-cement is found to be superior and environmental friendly approach for improving the properties of recycled aggregates

Environmental implications of the use of bio-cement treated recycled aggregate in concrete

Use of aggregates from recycled construction and demolition wastes in concretes alleviates the disposal problem and reduces the cost of concrete significantly. However, excessive water absorption, weak interfacial transition zone, and high porosity are its shortcomings. This study explores a bacterial cement and conventional cement slurry coating treatment on recycled coarse aggregates (RCA) for overcoming these shortcomings. In the first method, microbial carbonate precipitation (MCP) through bio-mineralization treatment has been utilized. Four different concretes were made using both control and treated aggregates. Once the performance of these concrete mixes was found adequate, a life cycle assessment was conducted using ISO14040–44 guideline to determine their environmental impacts. The experimental results confirmed that concrete with MCP treated aggregate offered better material performance than the untreated recycled aggregate based concrete mixes and possessed similar properties as natural aggregate concrete. While MCP process avoided the use of energy intensive cement, this research discovers that concrete with MCP treated aggregates was found to produce marginally higher environmental impacts than other concrete mixes mainly due to additional emissions associated with the bio-cement treatment of RCA. Further environmental mitigation strategies for concrete with MCP treated aggregates has considered to improve its environmental performance in terms of global warming impact and cumulative energy demand. This study demonstrates that the use of 100% RCA delivers significant environmental benefits in terms of ecological footprints, land conservation and biodiversity in a densely populated region like India