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From page 85... ... B-1 Proposed Guidelines for Use of Self-Consolidating Concrete in Cast-in-Place Bridge Components These proposed guidelines are the recommendations of the NCHRP Project 18-16 staff at the University of Nebraska-Lincoln. These guidelines have not been approved by NCHRP or any AASHTO committee nor formally accepted for adoption by AASHTO. Read the entire page →
From page 86... ... B-2 c o n t e n t s B-4 Introduction B-4 B.1 Guidelines for Selection of Constituent Materials B-4 B.1.1 General B-4 B.1.2 Cement, Supplementary Cementitious Materials, and Fillers B-4 B.1.3 Fine Aggregates and Coarse Aggregates B-4 B.1.4 Chemical Admixtures B-4 B.1.4.1 High-Range Water-Reducing Admixtures B-5 B.1.4.2 Air-Entraining Admixtures B-5 B.1.4.3 Viscosity-Modifying Admixtures B-5 B.1.4.4 Workability Retaining Admixtures B-5 B.2 Guidelines for Mix Proportioning B-5 B.2.1 General B-5 B.2.2 Workability Targets B-6 B.2.3 Proportioning Approach B-8 B.2.4 Quality Assurance B-8 B.3 Guidelines for Testing Fresh Concrete B-8 B.3.1 General B-8 B.3.2 Rheology B-9 B.3.3 Filling Ability B-9 B.3.4 Passing Ability B-10 B.3.5 Static Stability B-10 B.3.6 Dynamic Stability B-10 B.3.7 Heat of Hydration B-10 B.3.8 Pumpability B-11 B.3.9 Time of Setting B-11 B.3.10 Workability Retention B-11 B.3.11 Formwork Pressure B-11 B.4 Guidelines for Hardened Properties B-11 B.4.1 General B-11 B.4.2 Compressive Strength B-12 B.4.3 Modulus of Elasticity B-12 B.4.4 Splitting Tensile Strength B-12 B.4.5 Modulus of Rupture B-12 B.4.6 Bond to Deformed Reinforcing Steel Bars B-12 B.4.7 Shear Resistance B-13 B.4.8 Drying Shrinkage B-13 B.4.9 Restrained Shrinkage B-13 B.4.10 Creep B-13 B.4.11 Durability Properties Read the entire page →
From page 87... ... B-3 B-14 B.5 Guidelines for Production and Construction B-14 B.5.1 General B-14 B.5.2 Quality Control of Constituent Materials B-14 B.5.3 Mixing Procedures B-14 B.5.4 Plant Quality Assurance B-14 B.5.5 Transportation Procedures B-15 B.5.6 Site Quality Assurance B-15 B.5.7 Placement Methods B-16 B.5.8 Formwork Considerations B-17 B.5.9 Finishing Techniques B-17 B.5.10 Curing Methods Read the entire page →
From page 88... ... B-4 Introduction Self-consolidating concrete (SCC) is highly flowable, non-segregating concrete that can spread into place, fill the formwork, and encapsulate the reinforcement without any mechanical consolidation (ACI 237R-07) Read the entire page →
From page 89... ... B-5 or E (water reducing and accelerating) in different dosages to achieve the target flowability. Read the entire page →
From page 90... ... B-6 guidelines on workability targets based on the geometric characteristics of the bridge component. The three-digit identification shown at the bottom of the tree represents the target workability with respect to filling ability (FA) Read the entire page →
From page 91... ... B-7 parameters. This method can be used in combination with ACI 211.1-91 Table 6.3.3 to estimate mixing water requirements for different NMSA; and ACI 237R-07 Tables 4.1 and 4.2 to verify that the powder content, powder volume, and aggregate volume are within the recommended ranges for SCC. Read the entire page →
From page 92... ... B-8 2. Determine the optimal gradation of the combined coarse and fine aggregates that results in the highest density. Read the entire page →
From page 93... ... B-9 viscosity (µp) , which describes the ease/resistance of flow at a certain shear stress. Read the entire page →
From page 94... ... B-10 B.3.5 Static Stability Static stability describes the ability of SCC to maintain homogeneous distribution of its various constituents while being in the forms (at rest) Read the entire page →
From page 95... ... B-11 Despite the fact that SCC is more fluid than CVC, the higher pressure loss of SCC is attributed to the difference in the rheological properties of SCC and CVC (lower yield stress and higher viscosity and thixotropy) resulting in a different shear rate distribution and, consequently, a different velocity profile inside pipes (Feys, Verhoeven, and De Schutter, 2008) Read the entire page →
From page 96... ... B-12 at a given time (t) in days (fc) Read the entire page →
From page 97... ... B-13 strengths (4.0–8.0 ksi) Read the entire page →
From page 98... ... B-14 B.5 Guidelines for Production and Construction B.5.1 General Successful production and construction of cast-in-place bridge components using SCC requires more attention to the selection of materials, mixing and testing procedures, and placement and finishing methods than using conventional vibrated concrete. Trial batches are necessary to verify that SCC properties meet the target values/ranges and to make necessary adjustments to mixture proportions and/or production and construction procedures. Read the entire page →
From page 99... ... B-15 – A concrete truck is an effective method of placing SCC mixtures with all slump flow levels. Read the entire page →
From page 100... ... B-16 2. Skip with tremie pipe: – Insert a tremie pipe into the concrete in order to avoid the fall of fresh concrete into the forms. Read the entire page →
From page 101... ... B-17 HRWRA (Assaad and Khayat, 2005) Read the entire page →
From page 102... ... Abbreviations and acronyms used without deﬁnitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACI–NA Airports Council International–North America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing America's Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) Read the entire page →
From page 103... ... TRA N SPO RTATIO N RESEA RCH BO A RD 500 Fifth Street, N W W ashington, D C 20001 A D D RESS SERV ICE REQ U ESTED ISBN 978-0-309-37562-7 9 7 8 0 3 0 9 3 7 5 6 2 7 9 0 0 0 0 N O N -PR O FIT O R G . Read the entire page →

From page 85...

... B-1 Proposed Guidelines for Use of Self-Consolidating Concrete in Cast-in-Place Bridge Components These proposed guidelines are the recommendations of the NCHRP Project 18-16 staff at the University of Nebraska-Lincoln. These guidelines have not been approved by NCHRP or any AASHTO committee nor formally accepted for adoption by AASHTO.