DEPARTMENT OF THE ARMY ETL1110-2-343
U.S.Army Corps of Engineers
CECW-ED Washington,DC20314-1000
Engineer Technical Letter
No.1110-2-34331May1993
Engineering and Design
STRUCTURAL DESIGN USING THE ROLLER-COMPACTED
机械毕业设计
论坛CONCRETE(RCC)CONSTRUCTION PROCESS
1.Purpose
This engineer technical letter(ETL)provides guidance for design engineers considering roller-compacted concrete(RCC)as a cost-saving alterna-tive for civil works structures.
2.Applicability
This ETL applies to all HQUSACE elements,major subordinate commands,districts,laboratories,and separate field operating activities having civil works responsibilities for the design of civil works projects.
3.References
a.EM1110-2-2000,Standard Practice for Concrete.
我与名著b.EM1110-2-2006,Roller Compacted Concrete.
c.Draft EM1110-2-2200,Gravity Dam Design.
d.ETL1110-2-324,Special Design Provisions for Massive Concrete Structures.
e.ACI Committee207,Roller Compacted Concrete,207.5R,ACI Materials Journal, September-October1988.
f.ACI Committee210,Erosion of Concrete in Hydraulic Structures,ACI210R-87,ACI Materials Journal,March-April1987.
g.Heaton,B.S.1968(Oct).Strength,Dura-bility and Shrinkage of Incompletely Compacted Concrete,pp846-850.4.Purpose
RCC has developed over the past20years in response to the need to provide more economical mass concrete structures that can be constructed rapidly.RCC is replacing conventional mass con-crete as the primary construction material for gravity dams and has become a viable alternative material for structures other than dams.The enclosed guidance(Enclosure1)also provides design engineers with material considerations for RCC to assure that the completed structure meets strength and serviceability requirements.The enclosure includes:
a.Structural design guidance for RCC structures.
b.Examples of past usage and the types of structures suited to RCC construction.
c.Similarities and differences with respect to conventionally placed mass concrete.
d.The structural engineer’s role in the testing and construction processes.
e.Construction processes and features unique to RCC construction.
f.Material properties that affect strength,ser-viceability,durability,impermeability,and density.
g.Processes and procedures necessary to establish accurate strength parameters for design.
ETL1110-2-343 31May93
5.Recommendations and Requirements
a.Once strength and serviceability require-ments for the RCC have been established by the structural designers,in accordance with EM1110-2-2006,the structural design engineer should work with material engineers and the material testing laboratory to establish suitable mix designs,a com-prehensive laboratory and field testing program,and a quality assurance program to assure that the in-place RCC meets the design requirements.
b.Hydraulic structures require concrete that is durable and watertight,with moderate to high bond strength.To assure that the RCC will have these properties,the mix design should have:
马甲文化(1)Adequate paste and mortar to fill all aggre-gate voids.
(2)High slump mortar bedding on all lift joint surfaces.
(3)Aggregates meeting the standards for quality and grading as required for conventionally placed concrete.
Conventional concrete should be provided for regions where the RCC would be exposed to flow-ing water with velocities exceeding25fps and/or when flows are of significant duration and frequency to cause erosion and maintenance problems.Air-entrained conventional concrete should also be provided in all regions where the surface of the structure would be exposed to freeze-thaw cycles while critically saturated.
c.When RCC is used for massive concrete structures,the design objectives of ETL1110-2-324, "Special Design Provisions for Massive Concrete Structures"should be considered and a nonlinear structural analysis performed where required to meet design objectives.
d.Test placements during the mixture design phase and during the initial phase of construction are needed to verify adequacy of the mixture ingre-dients,mixture proportions,and construction techniques.
e.Consultation with and approval by
CECW-E is required when selecting consultants outside the Corps of Engineers for recommenda-tions on RCC design and construction practices.
f.The special uplift and sliding stability requirements of Section9of the enclosure shall be followed when designing RCC gravity dams.
g.A Post-Construction Structural Report should be submitted as outlined in Section9d of the enclosure.
FOR THE
DIRECTOR:
昌平二中分校1Encl PAUL D.BARBER,P.E.
Chief,Engineering Division
婴幼儿
营养与保健
Directorate of Civil Works
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