Performance assessment of agile communication in construction

Research has shown that the lack of effective communication is one main reason why the construction industry worldwide is falling behind others in advancing productivity, safety and quality. The focus of this thesis is to experimentally test the effectiveness of innovative information technologies in bridging existing information chasms creating large barriers to advancing construction. First, an extensive field study of the state-of-practice on an Australian construction site was conducted to identify the present information and material flows, information sinks, and sources related to rebar and concrete operations. The result of this initial field work was used to develop the Holonic Construction Management Model (HCMM) augmenting existing information models with the goal to create a unified umbrella able to support clearly identified data needs. The second phase of the work focused on testing four hypotheses. Building on the HCMM and the challenges of an active construction site, an Agile Site Communication Network (ASCNet) was created establishing the data conduits needed to connect the identified islands-of-communication. Furthermore, the discovered need to link mobile process resources with each other as well as to the internet involved the development and testing of a novel Embedded Wireless Communication Platform (EWCP). Another essential component of the ASCNet were multi-purpose and mobile data/information hubs to be placed at the work-front. This triggered the design, fabrication and testing of an electronic Construction Kiosk (eCKiosk) equipped with a wide touch screen, digital video/audio, wireless data-acquisition from electronic sensors and a secure data link to the world-wide-web. A third capability involved RFID tags to be embedded into the concrete of a ready-mix truck identifying its spatial location after placement.Finally, the experimental IT capabilities were used to address the four hypotheses established in Chapter 3. The extensive survey of electromagnetic signal attenuation on the test site proved that the existing decay functions were too inaccurate to be applicable for a construction site. Reformulated power decay indices drastically increased the signal strength prediction by more than a factor of 10 thus validating hypothesis 1. RFID embedded rebar bundles shipped on a GPS equipped trailer tuck and staged using feed-forward process information increased the productivity of crane-lifting by over 20% and eliminated 5 hours waiting of the delivery trucks that had been observed. The EWPC attached to a crane hook proved the feasibility and effectiveness of the multi-channel real-time communication link between the moving hook-block, the operator, GPS tracking software and the internet. The test of ZigBee�s IEEE 802.15 protocol under field condition provided the background for a successful application to monitor remotely concrete temperature for several days. The electronic hub served as a critical link to the wireless sensors while the RFID tags could be found after 4 days in the curing concrete and their locations automatically traced using a DGPS. Testes at the laboratory showed that doubling the amount of reinforcing steel in a concrete block scarifies 61% of detection range of the embedded tags.The tests on two construction sites not only improved our understanding of how to model wireless networks but proved that: a) A fatal blind-spot for crane operators can be immediately eliminated, b) time and safety risks during the delivery and staging of rebar can be drastically reduced, c) embedded RFID tags in combination with DGPS automate as-built data generation for concrete, and most importantly d) the high performance agile communication technologies of an eCKiosk and ZigBee sensor networks enable the effective coordination of on- and off-site activities. The latter two findings will open the door to cutting large process wastes through feed-forward supply-chain integration.