Replies

1. GBA编辑
   Martin Holladay|May 05, 2015 09:05am|#1

   Sural,
   这种类型的建筑系统已经在for years, but is rarely used in the U.S. because of its high cost. The 3D system uses EPS panels covered on both sides with welded-wire mesh; once erected on the job site, they are finished on both sides with concrete -- usually 1.5 to 3 inches of shotcrete or gunite (that is, a special concrete mix that is applied by a equipment that propels the concrete at a high velocity).

   成品建筑物相对密封，因此可以节能。像所有混凝土建筑物一样，这些建筑物耐用并抵抗风暴破坏。但是它们很昂贵。

   In India, you will need shotcrete equipment, or will have to modify the usual method of construction used in the U.S., and apply the concrete with a trowel.

   我写了一篇有关2004年4月发行的施工系统的文章Energy Design Update. In part, here is what I wrote:

   “两个制造商，3-D面板和Hadrian Tridi系统，生产墙板，这些墙面板上包含一个夹在两层焊接网格之间的聚苯乙烯芯。一旦将面板竖立在现场，它们就会在内部和外部涂上ShotCrete。

   "Hadrian TriDi Systems and 3-D Panel produce similar wall panels. Both companies manufacture their panels using machinery made by Entwicklungs Verwertungs Gesellschaft (EVG), the Austrian company that developed the wall system. Located in Brunswick, Georgia, 3-D Panel was formerly known as Insteel Construction System (see EDU, January 1992 and November 1992). Although Hadrian TriDi Systems operates out of Vista, California, its production plant is in Mexicali, Mexico.

   “大多数3 d板有一个核心的聚苯乙烯density of 1 pound per cubic foot, although customers interested in higher R-values can order panels with polyisocyanurate cores. Panels can be manufactured with foam cores ranging in thickness from 2 to 6 inches, with 4 inches being typical. Panel width is always 4 feet, and most panels are between 8 feet and 25 feet long. (Panels as long as 40 feet can be manufactured.) Since panels are installed vertically, the desired ceiling height determines the length of the panel needed. The walls of multistory buildings are continuous; for example, a one-story house with a basement usually requires 18-foot-long panels.

   "At the factory, the polystyrene core is sandwiched between two layers of 11-gauge 2” by 2” welded-wire steel mesh. The mesh layers are connected by a series of steel or plastic connectors that pierce the polystyrene, creating a three-dimensional cage with the foam at the center; the mesh stands about 3/4 inch proud of the foam. While Hadrian TriDi Systems uses steel connectors, 3-D Panel uses plastic connectors to reduce thermal bridging.

   "The wall panels are erected on a concrete footing or slab. The manufacturer specifies that vertical #3 rebar stubs, 24 inches on center, should protrude about 16 inches out of the concrete along all of the exterior walls. The panels are relatively light, and are usually lifted by hand over the rebar stubs, which fit between the polystyrene core and one of the layers of mesh (see Figure 1). Once plumb, the panels are secured with temporary diagonal braces. Seams between panels are then covered with strips of 2” by 2” splicing mesh; when installed at inside or outside corners, the strips of splicing mesh include a 90-degree bend.

   "Window and door openings are cut on site, using bolt cutters or a reciprocating saw to cut the mesh, and a handsaw to cut the foam. Typically, pressure-treated lumber frames are set in the window rough openings before shotcrete is sprayed (see Figure 2). Window headers narrower than 6 feet usually require no rebar reinforcement.

   “在墙壁涂有shotcrete之前，需要安装电管和电箱。要为导管腾出空间，丙烷火炬用于熔化聚苯乙烯中的通道。

   “一旦面板是垂直的，已经安装了支撑并安装了导管，面板两侧的网格都涂有1 1/2英寸至3英寸厚的shotcrete或gunite层，带有或没有塑料纤维增强。（当Shotcrete被抽水时，gunite被泵入干燥，在喷嘴处混合水。）通常指定了2,500 psi混凝土（见图3）。

   "In remote areas without access to shotcrete equipment, the concrete may be hand-troweled onto the 3-D panels. Like ICFs, 3-D panels can be used below grade; like SIPs, the panels can be used for roofs, although most 3-D buildings include conventional truss roofs. The maximum pitch for a 3-D panel roof is about 4 in 12. Roof panels are temporarily supported with purlins and shoring until the underside of the roof can be coated with shotcrete, and the concrete roof deck can be poured."

2. 
   Suraj Kaul|May 06, 2015 02:31am|#2

   亲爱的马丁
   感谢您提供的宝贵信息。但是，我仍然无法完全理解为什么已经使用该技术的非洲国家将这项技术称为具有成本效益。

3. GBA编辑
   Martin Holladay|2015年5月6日04:21 AM|#3

   Sural,
   Cost-effectiveness depends on available alternatives. It's possible that alternatives used in the U.S. -- for example, framing lumber -- are more expensive in some African countries than in the U.S. For example, I imagine that framing lumber isn't very cheap in Mali or Sudan.

4. 专家成员
   Dana Dorsett|2015年5月6日下午05:17|#4

   The generic term for this type of construction goes by the acronym "SCIP" , for "Structural Concrete Insulated Panels". A web search "SCIP" with the "concrete" as a second search term will find dozens of manufacturers and many industry articles in several countries.

   它比用墓地或混凝土块建造更昂贵，但是由于它是钢制钢筋混凝土单焦油，因此对飓风 /错别字或地震部队的弹性要远远有所，而且水泥比许多其他弹性墙壁都要少。EPS核心的热绝缘特性使其在热带区域中具有可比性或更好的热性能作为更大的泥浆/石材结构。水泥和混凝土混合设备的成本和可用性可以使SCIP比在某些地区更大的混凝土墙更具经济性。

   使用SCIP制造的不需要昂贵的射击设备。使用少量混合物，可以使用较轻的灰泥 /砂浆喷涂工具（请参阅http://www.mortarspra​​yer.com/diy-shotcrete/），也可以用手将其压紧，无需电力设备。在较高的劳动力国家中，手动施用价格昂贵，在较贫穷的地区少得多。在美国的建设中，劳动力在非洲大部分地区的成本很多倍，使较重的占名混凝土喷雾器便宜（尽管在这里比其他一些常见的建筑都要贵。）

   Buildings that are more than one story with SCIP is possible, but the specifications of the concrete & steel reinforcements and how the walls/floors/roofs tie together become more important as the amount of weight it as to support grows. In the US it is still not common enough that code officials are often uncomfortable with it unless the design specifications have been verified by an independent structural engineer, which adds to the cost of construction.

5. 
   Suraj Kaul|2015年5月7日上午08:29|#5

   Dear Dana
   感谢您提供有关使用替代工具进行shotcrete的宝贵信息。请帮助我使用其他替代工具或技术，以使其更具成本效益。另外，在我的研究中，我知道，提供生产EPS面板的机器，即Schnell和Emmedue，但是您是否知道其他提供EPS制造机器的公司。