Mundane Mobilities in ‘Post-Socialist’ Sofia: Making Urban Borders Visible

This article reflects on an on-going research project which aims to expand the understanding of the production and transformation of urban borders in the Eastern European cities of the ex ‘communist bloc’, starting from the case of Sofia. It explores the proposition that there has been a prolific process of wall making in this city associated with ‘vanishing public spaces’, ‘rescaling of enclosure’, and ‘corrosion of the collective urban realm’ (Hirt, 2012). The paper seeks to understand the social and political effects of this process by delving into the sensorial, emotional and embodied experiences associated with the mundane mobilities of urban residents. Using participants’ self-directed photography and videos from ‘walk-along’ interviews it explores the ways in which borders are made visible and are produced, challenged or resisted through mobility, and delves into the associated senses of deepening social and spatial differentiation in the city.

Post-tensioning of glulam timber with steel tendons

This paper describes a series of four-point bending tests that were conducted, under service loads and to failure, on unreinforced, reinforced and post-tensioned glulam timber beams, where the reinforcing tendon used was 12 mm diameter toughened steel bar. The research was designed to evaluate the benefits offered by including an active reinforcement in contrast to the passive reinforcement typically used within timber strengthening works, in addition to establishing the effect that bonding the reinforcing tendon has on the materials performance.

The laboratory investigations established that the flexural strength and stiffness increased for both the reinforced and post-tensioned timbers compared to the unreinforced beams. The flexural strength of the reinforced timber increased by 29.4%, while the stiffness increased by 28.1%. Timber that was post-tensioned with an unbonded steel tendon showed a flexural strength increase of 17.6% and an increase in stiffness of 8.1%. Post-tensioned beams with a bonded steel tendon showed increases in flexural strength and stiffness of 40.1% and 30% respectively.

Post-tensioning glulam timber beams with basalt FRP tendons

Improvements in the structural performance of glulam timber beams by the inclusion of reinforcing materials can increase both the service performance and ultimate capacity. This paper describes a series of four-point bending tests conducted, under service loads and to failure, on unreinforced, reinforced and post-tensioned glulam timber beams, where the reinforcing tendon used is 12 mm dia. basalt fibre-reinforced polymer. The research is designed to evaluate the benefits offered by including an active reinforcement in contrast to the passive reinforcement typically used within timber strengthening works, in addition to establishing the effect that bonding the reinforcing tendon has on the material's performance. Further experimental tests have also been developed to investigate the long-term implications of this research, with emphasis placed upon creep and loss of post-tensioning; however, this is ongoing and is not presented in this paper. The laboratory investigations establish that the flexural strength and stiffness increase for both the unbonded and bonded post-tensioned timbers compared to the unreinforced and reinforced beams. Timber that is post-tensioned with an unbonded basalt fibre-reinforced polymer tendon shows a flexural strength increase of 2ṡ8% and an increase in stiffness of 8ṡ7%. Post-tensioned beams with a bonded basalt fibre-reinforced polymer tendon show increases in flexural strength and stiffness of 15ṡ4% and 11ṡ5% respectively.

POST-TENSIONING OF TIMBER BEAMS WITH BASALT FIBRE REINFORCED POLYMER

Improvements in the structural performance of glulam timber beams by the inclusion of reinforcing materials can improve both the service performance and ultimate capacity. In recent years research focusing on the addition of fibre reinforced polymers to strengthen members has yielded positive results. However, the FRP material is still a relatively expensive material and its full potential has not been realised in combination with structural timber. This paper describes a series of four-point bending tests that were conducted, under service and ultimate loads, on post-tensioned glulam timber beams where the reinforcing tendon used was 12 mm diameter Basalt Fibre Reinforced Polymer (BFRP). The research was designed to evaluate the additional benefits of including an active type of reinforcement, by post-tensioning the BFRP tendon, as opposed to the passive approach of simply reinforcing the timber beam.
From the laboratory investigations, it was established that there was a 16% increase in load carrying capacity, in addition to a 14% reduction in deflection under service loads when members containing the post-tensioned BFRP composite are compared with control timber specimens. Additionally a more favourable ductile failure mode was witnessed compared to the brittle failure of an unreinforced timber beam. The results support the assumption that by initially stressing the embedded FRP tendon the structural benefits experienced by the timber member increase in a number of ways, indicating that there is significant scope for this approach in practical applications.

Development of Novel Post-Tensioned Glulam Timber Composites

Improvements in the structural performance of glulam timber beams by the inclusion of reinforcing materials can increase both the service performance and ultimate capacity. In recent years research focusing on the addition of fibre reinforced polymers (FRP) to strengthen members has yielded positive results. However, the FRP material is still relatively expensive and its full potential in combination with structural timber has not been realised. This paper describes a series of four-point bending tests that were conducted, under service loads and to failure, on unreinforced, reinforced and post-tensioned glulam timber beams, where the reinforcing tendon used was 12mm diameter basalt fibre reinforced polymer (BFRP). The research was designed to evaluate the benefits offered by including an active reinforcement in contrast to the passive reinforcement typically used within timber strengthening works, in addition to establishing the affect that bonding the reinforcing tendon has on the material’s performance. Further experimental tests have been developed to investigate the long-term implications of this research, with emphasis placed upon creep and loss of post-tensioning.
The laboratory investigations established that the flexural strength and stiffness increased for both the unbonded and bonded post-tensioned timbers compared to the unreinforced beams. Timber that was post-tensioned with an unbonded BFRP tendon showed a flexural strength increase of 2.8% and an increase in stiffness of 8.7%. Post-tensioned beams with a bonded BFRP tendon showed increases in flexural strength and stiffness of 16.6% and 11.5% respectively.

Building Trust in a Post-Conflict Society: An Integrative Model of Intergroup Contact and Intergroup Emotions.

Across one longitudinal and two cross-sectional surveys in Northern Ireland, we tested a model of intergroup relations in which out-group attitudes and behavioral tendencies are predicted by cross-group friendship and positive intergroup appraisals, mediated by intergroup emotions and out-group trust. In study 1, out-group friendship at time 1 predicted out-group trust at time 2 (one year later), controlling for prior out-group trust. In study 2, positive and negative intergroup emotions mediated the effects of friendship on positive and negative behavioral tendencies and attitudes. In study 3, a confirmatory factor analysis indicated that trust and emotions are distinct constructs with unique predictive contributions. We then tested a model in which cross-group friendship predicted intergroup emotions and trust through intimate self-disclosure in out-group friendships. Our findings support an integration of an intergroup emotions framework with research highlighting the importance of cross-group friendship in fostering positive intergroup outcomes.