Item 410 Concrete Structures.docx

1、Item 410 Concrete StructuresItem No. 410SConcrete Structures410S.1 Description This item shall govern the construction of all types of structures involving the use of structural concrete, except where the requirements are waived or revised by other governing specifications.All concrete structures sh

2、all be constructed in accordance with the design requirements and details indicated on the drawings, in conformity with the pertinent provisions of the items contracted for, the incidental items referred to and in conformity with the requirements herein.This specification is applicable for projects

3、or work involving either inch-pound or SI units. Within the text and accompanying tables, the inch-pound units are given preference followed by SI units shown within parentheses.410S.2 Submittals The submittal requirements of this specification item may include:Appropriate mix designs for class of c

4、oncrete for each type of structure or unit;Appropriate mortar and grout mix designs;Product name, description, technical information and supplier of any acrylic-polymer latex admixture;Type, supplier and certified test results for expansion joint materials;Type of waterstop and confirmation that the

5、 product conforms to TxDoT DMS-6160;Type and manufacturer of proposed evaporation retardant and confirmation that it meets the requirements of test results for TxDoT DMS-4650;Type and manufacturer of proposed chemical admixtures and confirmation that it meets the requirements of test results for TxD

6、oT DMS-4640;Type and manufacturer of proposed curing admixtures and confirmation that it meets the requirements of test results for TxDoT DMS-4640;Type and manufacturer of proposed chemical admixtures and confirmation that it meets the requirements of test results for TxDoT DMS-4640;Type and manufac

7、turer of proposed epoxy and/or adhesives and confirmation that it meets the requirements of test results for TxDoT DMS-6100;Reinforcing steel shall conform to Standard Specification Item No. 406S, “Reinforcing Steel”.Contractors formwork plan for placing and consolidating concrete around wall penetr

8、ations and at locations designated as having congested reinforcing steel.410S.3 MaterialsA. Concrete Concrete shall conform to Item No. 403S, Concrete for Structures.The class of concrete for each type of structure or unit shall be as indicated on the drawings or by pertinent governing specification

9、s.B. Grout or MortarWhen required or shown on the drawings, mortar and grout consisting of 1 part hydraulic cement and 2 parts sand with sufficient water to provide the desired consistency shall be provided. Mortar shall be provided with a consistency that can be handled easily and spread by a trowe

10、l. Grout shall be provided with a consistency that will flow into and completely fill all voids.C. LatexWhen required an acrylic-polymer latex admixture (acrylic resin emulsion in accordance with TxDoT DMS-4640, “Chemical Admixtures for Concrete”) suitable for producing polymer-modified concrete or

11、mortar shall be provided. The latex shall not be allowed to freeze.The following information shall be submitted for latex:Name and information of company contact personnel,Product name and polymer description, andThe latex shall meet the following requirements.Table 1: LATEX ADDITIVE REQUIREMENTSPro

12、pertyValueTotal Solids, minimum, percent47PH9.0 to 11.0Brookfield viscosity (# 1 spindle 10 rpm), mPas, maximum60Butadiene Content, percent30 to 40Freeze-thaw stability, 2 cycles. maximum0.1Specification targets and production tolerances shall also be provided for the following properties.1. viscosi

13、ty (including test method and temperature reference),2. percent solids,3. pH,4. specific gravity, and5. styrene/butadiene ratio.D. Reinforcing SteelReinforcing steel shall conform to Standard Specification Item No. 406S, “Reinforcing Steel”.E. Expansion Joint MaterialThe expansion joint material sha

14、ll conform to the requirements of TxDoT DMS-6310, “Joint Materials and Fillers”.1. Preformed Fiber SheetsUnless otherwise indicated on the drawings preformed bituminous fiber material shall be provided. The preformed fiber material shall conform to the dimensions indicated on the drawings. Preformed

15、 fiber sheets shall meet the requirements of ASTM D-1751, “Preformed Expansion Joint Filler for Concrete Paving and Structural Construction (Nonextruding and Resilient Bituminous Types). The requirements related to bitumen content, density and water absorption shall not apply to nonbituminous materi

16、als. 2. Joint Sealing MaterialUnless otherwise indicated on the drawings a Class 4, 5 or 7 low-modulus silicone sealant shall be provided that conforms to the requirements of TxDoT DMS-6310, “Joint Sealants and Fillers”.3. Timber BoardsTimber boards shall be made from redwood or cypress and must be

17、free from sapwood, knots, clustered birds eye, checks and splits. When oven dried at 230oF (110oC) to a constant weight (mass), the density of the board shall be between 20 and 35 lbs. Per cubic foot (between 320 and 560 kgs per cubic meter)4. Asphalt BoardAsphalt Board shall conform to the dimensio

18、ns indicated on the drawings and shall meet the description, general requirements and distortion testing of ASTM D-994, “Preformed Expansion Joint Filler for Concrete (bituminous Type)”. 5. Rebonded Neoprene Filler SheetRebonded neoprene filler shall consist of ground closed cell neoprene particles,

19、 rebonded and molded into sheets of uniform thickness of the dimensions indicated on the drawings. These sheets shall meet the requirements of ASTM D-1752, Type I.The manufacturer shall furnish the Engineer or designated representative with certified test results as to the compliance with the above

20、requirements.F. Waterstop Unless otherwise indicated on the drawings, rubber waterstops or Polyvinyl Chloride (PVC) waterstops that conform to TxDoT DMS-6160, “Waterstops, Nylon Reinforced Neoprene Sheet, and Elastomeric Pads” shall be provided.G. Evaporation RetardantsEvaporation retardants shall c

21、onform to the requirements of TxDoT DMS-4650, “Hydraulic Cement Concrete Curing Materials and Evaporation Retardants”. The evaporation retardant must be a commercially available monomolecular film compound. The evaporation retardant shall have no adverse effect on the cement hydration process or the

22、 concrete and shall reduce surface moisture evaporation from the concrete when performing concrete operations in direct sun, wind, high temperatures, or low relative humidity. The producer of the evaporation retardant shall certify that it meets these specified requirements.H. Curing Materials 1. Li

23、quid Membrane Forming compounds Liquid Membrane Forming compounds shall conform to the requirements of TxDoT DMS-4650, “Hydraulic Cement Concrete Curing Materials and Evaporation Retardants”. The compound shall be applied to damp concrete as a fine mist through atomizing nozzles at a wet film thickn

24、ess of 8 to 9 mils (200 to 230 m). The liquid membrane-forming compound must not react deleteriously with concrete or its components. It must produce a firm, continuous, uniform moisture-impermeable film that is free of pinholes, cracks, or other film defects. It must also exhibit satisfactory adhes

25、ion.The consistency must be such that the compound can be applied satisfactorily by conventional or airless spray at atmospheric and material temperatures above 40oF (5oC) without thinning. When applied at the manufacturers recommended thickness, not less than 8 mils (200 m) wet, to vertical surface

26、s of damp concrete, the compound must not run off or appreciably sag. The liquid membrane-forming compound must not disintegrate, check, peel, or crack during the required curing period. It must not peel or pick up under traffic, and must disappear from the surface of the cured concrete by gradual d

27、isintegration.2. Cotton Mats Cotton mats shall consist of a filling material of cotton “bat” or “bats” at least 12 oz. Per square yard (400 grams per square meter) completely covered with unsized cloth at least 6 oz. Per square yard (200 grams per square meter) stitched longitudinally with continuou

28、s parallel rows of stitching spaced at less than 4 in. (100 mm), or tuft both longitudinally and transversely at intervals less than 3 in. (75 mm). The cotton mats shall be free from tears and in good general condition. A flap at least 6 in. (150 mm) wide with two (2) thicknesses of the covering tha

29、t extends along one side of the mat shall be provided.3. Polyethylene SheetingThe polyethylene sheeting shall be at least 4 mils thick (0.1 mm) and free from visible defects. Clear or opaque white sheeting shall be provided when the ambient temperature during curing exceeds 60oF (15oC) or when appli

30、cable to control temperature during mass pours.4. Burlap-Polyethylene Mats The burlap-polyethylene mats shall be made from burlap impregnated on 1 side with a film of opaque white-pigmented polyethylene, free from visible defects. The laminated mats shall have at least 1 layer of an impervious mater

31、ial such as polyethylene, vinyl plastic, or other acceptable material (either as a solid sheet or impregnated into another fabric) and shall be free of visible defects.I. Chemical AdmixturesChemical admixtures including water reducing, placticizers and air entrainment shall conform to TxDoT DMS-4640

32、, “Chemical Admixtures for Concrete” Calcium chloride shall not be used. Admixtures shall be included in the prequalified concrete admixtures list maintained by TxDots Construction Division.J. City of Austin Survey Monuments The Public Works Department may furnish permanent survey monuments to be cast in concrete as indicated on the drawings or as directed by the Engineer or designated representative.K. Epoxy Unless indicated otherwise on the drawings, epoxy materials shall conform to TxDoT DMS-6100, “E