The American Concrete Institute is seeking comments by Jan. 17 on the 2011 update of its standard ACI 318, Building Code Requirements for Structural Concrete and Commentary. Among other additions, the draft includes new design requirements for adhesive anchors and enhanced reinforcement detailing requirements for seismic applications. The document also contains new test methods for sulfate resistance and new requirements for detailing circular column ties. The draft ACI 318-11 can be downloaded at www.concrete.org/pubs/standaction.asp.
The Precast/Prestressed Concrete Institute, concerned about an ominous pattern of spandrel-ledge-punching sheer failures in lab tests of double-tee spandrel-beam assemblies commonly found in parking garages, plans to spend approximately $200,000 to further investigate the situation. During tests on torsion design of loadbearing spandrel beams, punching sheer failures in spandrel ledges occurred at loads substantially less than those predicted by PCI Handbook design equations, according to the institute. No failures have been reported from the field, says PCI. The group, which plans to foot two-thirds of the bill for research costs, is seeking funding from other sources.
Railroad maintenance crews in the U.K. have been using sprayed polymer to strengthen track ballast for about a decade. One contractor now aims to go one step further and use strengthened ballast as a non-intrusive reinforcement for some of the country’s 25,000 aging brick-and-stone arch bridges. Balfour Beatty Rail Ltd., Redhill, is offering a method to treat a bridge and its polymer-coated ballast as a composite structure. The resulting enhanced strength of the arch can eliminate the need for concrete or steel reinforcement, says Andy Curzon, BBR’s head of technical services. The technique, called XiSPAN, would preserve the appearance of
Researchers in Northern Ireland report promising results from a demonstration project that used rods made with basalt fibers to reinforce a 22-meter-long concrete-deck section of a $1.5-million replacement bridge in County Fermanagh. The mineral material, which resists corrosion and has twice the tensile strength of steel, is not yet accredited for structural use in the U.K. In addition to testing the basalt-fiber-reinforced polymer (BFRP), the project is a demonstration of compressive membrane analysis in deck design, says Susan Taylor, a senior structural-engineering lecturer at Queen’s University, Belfast, which secured a $160,000 grant from the U.K. Dept. for Transport for the
China continued its investment in Africa’s infrastructure—and in South Africa’s deep need for cement—when a Chinese cement maker formed a partnership to build a plant with two South African companies. Jidong Development Group, the largest cement producer in northern China, has signed a partnership with South Africa’s leading black-women-owned company, Women Investment Portfolio Holdings Limited (WIPHOLD), and with limestone mining firm Continental Cement. The deal is for construction of a new $218-million cement plant in Limpopo, the northernmost province of South Africa. The venture for the 2,500-tons-a-day cement facility also involves the China-Africa Development Fund (CAF Fund), a leading Chinese
An American architecture professor at a university in the Middle East is developing an energy-saving way to make bricks using bacteria known for its ability to solidify sand.
Already scrambling for highway funding, state departments of transportation and road contractors now are stymied by a nationwide shortage of pavement-marking paint. Photo: WSDOT Highway contractors are coming up short because of kinks in the road-paint supply chain, thanks to recession and a critical chemical shortage. The source of the shortfall is a mixture of economics, chemistry, production disruptions and international trade, and the result will likely be rationed paint and higher prices through most of the summer—and perhaps beyond. Brian Deery, senior director of the Highway & Transportation Division at the Associated General Contractors of America, says DOTs may
At the site of a new $8.5-million, three-story dormitory at Southern Nazarene University in Bethany, Okla., the Versa-Floor HR floor system is getting its first real-world application. The prefabricated steel deck is joined and fitted with channels on the ground. Then, the 30 x 30-ft steel panels are lifted into place by a crane. Once connections are made to the structural columns, it’s almost ready for the concrete slab to be poured. “That’s the genius of the system,” says Aaron Ford, project manager on the dormitory project and associate principal with structural engineering firm L.A. Feuss Partners, Dallas. “We build
A structural engineer is poised to be the first to use steel fibers as structural reinforcing in the lateral-force-resisting system of a concrete-framed high-rise in a seismic zone. The application, designed to reduce reinforcing-steel congestion in shear-wall link beams and, perhaps, in shear walls themselves, is based on recent successful performance tests of SFRC link beams at the University of Michigan, Ann Arbor. Photo: Bekaert Corp. Specimen Steel-fiber reinforcing can eliminate 40% of rebar in link beams in seismic frames. Image: Cary Kopczynski & Co. It also allows diagonal rebar to be smaller and more bendable, so it can exit
The warning shot came in a federal court in Louisiana, and it may signal the beginning of the end of one more costly aspect of the homebuilding boom of 2004-2007. Federal Judge Eldon Fallon in New Orleans ordered Taishan Gypsum Co. Ltd. to pay seven Virginia families a total of $2.6 million to remediate defective Chinese-made drywall in their homes. The case is the first of several class-action lawsuits filed against manufacturers of material that has proven to be a veritable nightmare—and source of odors—for thousands of home-owners. + Image Source: U.S. Consumer Product Safety Commission Photo: AP/Wideworld Consumer Product