F. Javier Baeza

Triple Percolation in Concrete Reinforced with Carbon Fiber

This article discusses how the electrical resistivity of carbon fiber (CF) reinforced concrete with electrical continuity within the cement paste and sand-cement ratio (s/c) 0.75 depends on the CF content and gravel-sand ratio (g/s). For resistivity ≤500 Ω.cm, the mortar must exceed 62 vol.% and the cement paste must exceed 44 vol.%. The minimum resistivities provided by double percolation (continuity provided by the cement paste in the mortar but no continuity of either paste or mortar), pseudo triple percolation (continuity provided by the cement paste of the mortar), and true triple percolation (continuity provided by the mortar) are 355, 36, and 7.6 Ω.cm, respectively. The true triple percolation threshold is 0.75% CF (by mass of cement) if g/s ≤1.50 and 1.5% CF if g/s ≤2.00. The pseudo triple percolation threshold is 1.5% CF if g/s = 2.50 and 1.75% CF if g/s = 2.50 to 3.00. The double percolation threshold is 0.75% CF if g/s = 2.00 to 3.00.

Seismic Behavior of a Masonry Chimney with Severe Cracking Condition: Preliminary Study

This paper presents a structural analysis of a masonry chimney built in the 1940s, which is currently being cataloged as local interest heritage. This structure has not served any industrial purpose for the last thirty years. The chimney is located in the town of Agost (Alicante - Spain) and directly exposed to the prevailing winds from the sea, as it is approximately 12 km away from the waterfront and there are not any significant barriers, which could protect the structure against the wind. There are longitudinal cracks and fissures all along the shaft because of the chimney’s geometrical characteristics, the effect of the masonry creep and especially the lack of maintenance. Moreover, there is also a permanent bending deformation in the upper 1/3 of the height due to the wind pressure. A numerical analysis for the static behavior against gravity and wind loads was performed using the structure’s current conditions after a detailed report of its geometry, its construction system and the cracking pattern. Afterwards, the dynamic behavior was studied, i.e. a seismic analysis using both response spectra and accelerograms in order to examine the structural stability. This work shows the pre-monitoring analysis before any experimental testing. Using the current results the future test conditions will be determined (e.g. number of sensors and monitoring point location, excitation systems, etc) prior to a possible structural reinforcement by applying composite material (fiber reinforced polymers).

Structural Health Monitoring Systems for Smart Heritage and Infrastructures in Spain

The development of information and communication technologies (ICT) and robotics is currently demonstrating its potential impact on different fields of application. With regard to cultural heritage, and architectural and engineering heritage in particular, these new technologies are changing the possibilities for structural capacity assessment and health monitoring (SHM). The objective of smart heritage can be achieved thanks to properly designed SHM systems, which when connected to an automated diagnostic system can even self-evaluate retrofitting needs. This chapter includes a brief summary of the SHM technologies applied for cultural heritage management in Spain during the early 2000s.

BIM IMPLEMENTATION FOR STRUCTURAL DESIGN COURSES IN CIVIL ENGINEERING

Building information modelling (BIM) is a collaborative work methodology for the creation and management of a construction project. Its aim is to centralize all project information in a digital information model created by all agents involved in its development. BIM supposes the evolution of traditional design systems based on plans, since it incorporates geometric (3D), time (4D), costs (5D), environmental (6D) and maintenance (7D) information. Furthermore, BIM is not limited to the initial design phases, as it also covers the execution of the project and even the life cycle of the building. During the last decade, BIM methodology has been progressively implemented in different countries, becoming a priority for their Public Administrations. Following the recommendation of the European Directive of Public Procurement 2014/24/EU, BIM is progressively being requested in public works, e.g. The Spanish Ministry of Public works created in 2015 the National Committee of BIM, in which BIM implementation in the architecture, engineering and construction (AEC) industry and how to introduce it in public tenders are being considered. This progressive implementation of BIM by public administrations is transforming AEC industry. Therefore, universities should include BIM formation in AEC related studies, in order to prepare future engineers for this new scenario. In this work, a critical review of different approaches for BIM implementation in structural design of Civil Engineering Degree is made.