IB-P-BC 2002-031 Concrete Proportioning and Admixture - ladbs

P/BC 2002-031TABLE NO. 2 - ARBITRARY MIX PROPORTIONSAssumedCompressive Strength(psi)Maximum AggregateSize(In.)5000 13/84000 1 ½13/83000 1 ½13/82500 1 ½13/82000 1 ½13/8Minimum CementContent Sacks perCubic Yard8.59.27.17.37.96.06.26.85.45.56.35.05.25.8Maximum WaterContentGallons per Sack4.55.05.35.55.76.26.26.27.07.07.08.08.08.0IIAs authorized by LABC section 1903.6 the following method for qualifying admixtures is approved.Admixture Qualification Alternate:Alternate Admixture Qualification Method utilizes two concrete mixes: one with one-inch maximumaggregate and one with 3/8-inch maximum aggregate. Both mixes are to be tested with theadmixture and with a control mix of identical proportions except for omission of the admixture.Exception: For classification as a water reducing admixture, the cement content in the mixcontaining the admixture shall be reduced by 0.6 sack per cubic yard of concrete. Thewater content shall be adjusted so that the water/cement ratio is equal to that of the controlmix. If the resulting slump is less than that of the control mix, additional water shall beadded to provide equal slump.The one-inch maximum aggregate mix shall have a cement content of 5.6 sacks per cubicyard, and the 3/8-inch maximum aggregate mix shall have a cement content of 7½ sacksper cubic yard. Cement used shall be a uniform blend of cements obtained from fourseparate mills and shall conform to Type I, Type II or a blend of Type I and Type II cement.As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.Page 3 of 4

P/BC 2002-031The combined aggregate gradation shall conform to that specified in Table 1. Water contentof the control mix shall be adjusted to produce a slump of four inches.Compression tests shall be performed in accordance with ASTM Specifications C39 andC192 on standard 6" X 12" cylinders at the age of 28 days, one year and two years. Testsshall be conducted on at least three specimens for each age for each mix. The averagestrengths of the specimens containing the admixture shall at least equal the averagestrength of control specimens at each age.Note: Fly Ash may be combined with other admixtures and requires an approved L.A. CityResearch Report.As a covered entity under Title II of the Americans with Disabilities Act, the City of Los Angeles does not discriminate on the basis of disability and, upon request, will providereasonable accommodation to ensure equal access to its programs, services and activities. For efficient handling of information internally and in the internet, conversion to thisnew format of code related and administrative information bulletins including MGD and RGA that were previously issued will allow flexibility and timely distribution of informationto the public.Page 4 of 4