Sources: ASTM International, West Conshocken, Pa.; CP staff
ASTM Committee A01 on Steel, Stainless Steel and Related Alloys has approved the inclusion of grades 310, 325, 340 product in A416/A416M, Specification for Low-Relaxation, Seven-Wire Steel Strand for Prestressed Concrete, representing a 15- to 25-percent increase in minimum tensile strength from existing grades. A new annex in the standard will reference the three grades.
The New York City Buildings Department now recognizes structural designs using high strength Grade 100 concrete reinforcing steels. Through issuance of Buildings Bulletin 2015-036, Irvine, Calif.-based MMFX Steel Corp. of America notes, the city accepts designs employing the 100,000-psi yield strength of ASTM A1035/A1035M-15 rebar. The document clears the way for MMFX high strength ChrõmX rebar in a market ushering a wave of active or proposed tower projects whose slender profiles invite reinforced concrete design—owing especially to stiffness characteristics tempering sway.
Sources: BASF Admixture Systems, Cleveland; CP staff
MasterFiber MAC Matrix, a 2.1-in. long polypropylene macrofiber BASF Admixture Systems developed for secondary reinforcement of precast and cast-in-place structures, meets the performance requirements of a new ASTM C13 Committee on Concrete Pipe standard: C1818 Specification for Rigid Synthetic Fiber Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe.