Experimental study of full scale concrete wall construction using contour crafting.

摘要

During the last 18 years, construction automation and robotics have been implemented to various degrees to address problems facing the construction industry. Productivity, quality, safety, high costs and skilled labor shortages in the United States and Japan are serious concerns. Automation technologies have improved their performance, capability, and accuracy in recent years due to advances in sensing technology, numerical machine controllers, and automated drive systems. Today robotic systems routinely replace many complicated, tedious, and dangerous human tasks in a variety of fabrication applications, except construction. Conventional labor intensive construction processes do not allow efficient implementation of current automation technologies in construction fields with promising economic returns. Currently prototype construction robots are expensive and return minimal automation and economic benefits compared to the other types of industries.; This dissertation presents an innovative construction automation approach using a layered fabrication process called Contour Crafting (CC), developed at the University of Southern California. The CC technology adapts Rapid Prototyping (RP) capabilities and extends them to the field of large-scale fabrication such as residential and commercial construction. Using this process, a single house or a colony of houses, with varying structural designs, can be automatically constructed in a single run. CC is the only RP process suitable for fabrication of large-scale, complex shaped, smooth surface objects using a variety of materials.; In the CC construction process, a concrete wall form is built by adding mortar with embedding form ties; then a batch of concrete is poured layer by layer with a delay between batches. With the available construction speed in this research, a series of 10 feet tall concrete walls (normal height of residential housing) can be erected in a single day. The potential of CC became more evident through successful construction and testing of full-scale concrete wall sections.; The results show that CC construction has the capability of building full scale concrete walls suitable for residential housing. The conclusion is that the CC process has great potential in construction automation due to its relative simplicity, low cost, speed, and the capability of being easily integrated with currently available structure design and automation technologies.