Over the last thirty years, the use of strawbales as a construction material has re-gained a lot of popularity for several reasons: baled straw has superior thermal insulation properties; buildings made with straw-bales are less expensive; straw is a by-product, hence its usage can help reduce the costs and emissions related to its disposal; structures built with strawbales can resist earthquakes better than those built according to traditional techniques. In the context of using materials and techniques sustainable for the environment, strawbale construction appears a more than promising choice establishing a strong link with the territory as well. Indeed, straw has been extensively used as a construction material since pre-history; more recently, strawbale houses were built in Nebraska at the end of the 19th century. The use of strawbales in construction returned popular in the late 80's (King, 2003); in some countries, this has been also supported by the development of design standards. In Italy, the lack of similar codes represents an obstacle; the procedure to have a design approved is tedious and discourages builders. In spite of this, however, strawbale houses have been and are currently being built. A deep understanding of the mechanical behavior of straw and of the material typically used in the rendering of strawbale walls is crucial for the development of construction techniques employing load-bearing strawbale walls. In the literature, studies on the mechanical properties of strawbales and strawbale assemblies have appeared since the rediscovery of this construction technique (Zhang, 2000; Vardy, 2009). Such studies report results of experimental tests conducted on single bales and on stacks of multiple bales, plastered or unplastered, loaded both on-edge and flat. However, very few of them provide some modeling to substantiate the results. In this paper, a review of the relevant literature regarding the mechanical properties of single unplastered straw bales is proposed and critically analyzed in order to provide guidance for future modeling; furthermore, the procedure for a comparative LCA between the options of building with conventional materials and with straw bales is sketched out and preliminary results of such an analysis are discussed.
MECHANICAL BEHAVIOR OF STRAWBALES FOR USE IN CIVIL AND RURAL CONSTRUCTION
MARALDI, MIRKO;MOLARI, LUISA;MOLARI, GIOVANNI
2015
Abstract
Over the last thirty years, the use of strawbales as a construction material has re-gained a lot of popularity for several reasons: baled straw has superior thermal insulation properties; buildings made with straw-bales are less expensive; straw is a by-product, hence its usage can help reduce the costs and emissions related to its disposal; structures built with strawbales can resist earthquakes better than those built according to traditional techniques. In the context of using materials and techniques sustainable for the environment, strawbale construction appears a more than promising choice establishing a strong link with the territory as well. Indeed, straw has been extensively used as a construction material since pre-history; more recently, strawbale houses were built in Nebraska at the end of the 19th century. The use of strawbales in construction returned popular in the late 80's (King, 2003); in some countries, this has been also supported by the development of design standards. In Italy, the lack of similar codes represents an obstacle; the procedure to have a design approved is tedious and discourages builders. In spite of this, however, strawbale houses have been and are currently being built. A deep understanding of the mechanical behavior of straw and of the material typically used in the rendering of strawbale walls is crucial for the development of construction techniques employing load-bearing strawbale walls. In the literature, studies on the mechanical properties of strawbales and strawbale assemblies have appeared since the rediscovery of this construction technique (Zhang, 2000; Vardy, 2009). Such studies report results of experimental tests conducted on single bales and on stacks of multiple bales, plastered or unplastered, loaded both on-edge and flat. However, very few of them provide some modeling to substantiate the results. In this paper, a review of the relevant literature regarding the mechanical properties of single unplastered straw bales is proposed and critically analyzed in order to provide guidance for future modeling; furthermore, the procedure for a comparative LCA between the options of building with conventional materials and with straw bales is sketched out and preliminary results of such an analysis are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
