NRMCA Attends ACI Spring Convention, Provides Summary Report

The ACI Spring Convention in Kansas City, MO, was held during the week of April 12. Below is an update of some of activities that involved NRMCA representation.

130 – Sustainability Committee: Lionel Lemay maintains NRMCA representation on ACI 130. The main focus of the committee is to develop a guide to concrete sustainability. The committee can now ballot the entire guide. Several sections, including materials, production and construction, were previously balloted and therefore will not be subject to re-balloting. Lemay will continue to monitor this committee to ensure ready mixed concrete’s interests are maintained and performance specifications and life cycle assessment, including work at MIT are properly described and acknowledged.

132 – Responsibilities in Concrete Construction: ACI Committee 132’s document – ACI 132R-14 Guide for Responsibility in Concrete Construction – is available from ACI. It outlines responsibility of various stakeholders, including the owner, licensed design professional, general contractor, design/builder, subcontractor, specialty engineers and subcontractors, concrete material supplier, testing/inspection agency, construction manager and failure analysis consultant. The document discusses associated responsibility with prescriptive and performance specifications. Jeff Coleman will step down as chairman and names have been recommended for the new chairman. Colin Lobo maintains representation on ACI 132.

201 – Durability: The 201.2R Guide to Durable Concrete is being revised. All chapters have been completed; negatives on the chapter on corrosion were resolved. A sentence stating that other national standards consider chloride limits by percent cementitious and not by percent cement has been added.  NRMCA has provided input to this document.  A task group is working on a tech note for recommendations for physical salt attack. Future sessions are planned on the following: 1. Sulfate Attack; 2. Chloride Limits and Thresholds. Karthik Obla maintains representation on ACI 201.  

211 – Mixture Proportioning: The committee has completed several documents in the last year – Proportioning with Ground Limestone and Mineral Fillers; Guide to Troubleshooting Concrete Mixtures and Aggregates Suspension Mixture Proportioning Method. A new electronic document (E-doc) on Aggregate Suspension Mixture Proportioning method has been published. The committee is voting on a document on Mixture Proportioning for Pumpability. A task group working on assessing aggregate gradings issued a ballot and NRMCA provided input to the document based on past research conducted at the NRMCA Research Laboratory. A new task group was created to work on 3-point curves. The main 211 proportioning document is being revised with input from NRMCA. Karthik Obla maintains representation on ACI 211.

214 – Strength Tests: The committee plans to update the report with information on percent within limits concepts that are being used by some DOTs for allocating incentives and penalties. The committee decided to develop tech notes on two topics - strengths of cubes vs cylinders; and use of two 4x8 in. concrete cylinders for acceptance. Karthik Obla is as an associate member.

232 – Fly Ash: The committee will conduct an ACI Webinar on high volume fly ash (HVFA) concrete on Tuesday, June 9. The committee is working on a new document Guide to Specifying Fly Ash for Concrete Performance. The committee has successfully balloted revisions to the ACI 232.2R, Use of fly ash in concrete and the document will now go to TAC. Many sessions are planned in future conventions, including one to honor Tarun Naik in Milwaukee. Karthik Obla has completed his term as chairman of ACI 232 and will be followed by Larry Sutter.

240 – Natural Pozzolans: This new committee on natural pozzolans discussed whether to expand its scope and consider other supplementary cementitious materials like ground glass, rice hull ash etc. which are strictly not natural pozzolans. Several new sources of natural pozzolans are being talked about. Karthik Obla maintains representation on ACI 240.

301 – Specifications for Structural Concrete: ACI Committee 301 devoted considerable meeting time addressing comments on the revised specification from Technical Activities Committee (TAC). The specification was updated to reflect the ACI 318-14 Code requirements and several other improvements have resulted from this review. The committee will complete the resolution through web meetings and plans to have the document available for public comment in July. The ACI public comment period will be a 6-week duration. The committee plans to complete its resolution to public comments at the Fall Convention and publish the document early in 2016. Colin Lobo maintains representation on ACI 301.

318 – Building Code for Structural Concrete: With the release of ACI 318-14 and the establishment of the new committees, there is considerable work at the subcommittee level to work on improvements to the re-organized code. The chapters of interest to concrete producers are Chapter 19 that states requirements for concrete, including the durability provisions, and Chapter 26 that includes provisions that the designer needs to include in construction documents.

ACI 318 Subcommittee A on concrete materials discussed the following:  – clarifying acceptance requirements for strength, remove reference to ACI 301 for proportioning concrete, permitting the calculation of chlorides in lieu of testing to document conformance to chloride limits, and clarifying that water and admixtures do not have limits on chlorides. The subcommittee is also working on code proposals that will include shotcrete in the code, consideration of performance-based alternatives to w/cm ratio, consideration of elastic modulus of high strength concrete, revising the inspection provisions for concrete to be consistent with the International Building Code (with a goal that IBC will reference ACI 318), defining the lambda-factor for design with lightweight concrete based on equilibrium density, and considering different levels of specified strength for air-entrained and non air-entrained concrete based on the required w/cm for durability. Colin Lobo maintains representation on ACI 318 and ACI 318A.

325 – Concrete Pavements: NRMCA’s Brian Killingsworth maintains representation on ACI 325 on concrete pavements. The committee currently has seven documents under development or revision. The report ACI 325.9R Guide for Construction of Concrete Pavements has been completely revised and will be published in the next few months. The committee is also rewriting ACI 325.12R-02 (Reapproved 2014): Guide for Design of Jointed Concrete Pavements for Streets and Local Roads and is being led by Killingsworth. Revisions to this document will be completed this summer and balloted in the fall. The committee is also developing ACI 325.XR Report on Precast Concrete Pavements - State of the Practice which is based upon work completed by Tayabji for SHRP2. The committee is also developing ACI 325.YR Proportioning, Quality Control and Evaluation of Concrete Pavement Strength Relationships. The document is complete and is being prepared for publishing by ACI. A revision is underway of ACI 325.11R Accelerated Techniques for Concrete Paving. Work is nearly complete and will be balloted in the next few months. Work is also underway to update ACI 325.ZR: Design and Construction of Continuously Reinforced Concrete Pavements over the next year. Lastly, ACI 325.13R-06: Concrete Overlays for Pavement Rehabilitation is being reviewed and updated. This work will continue over the next year. Killingsworth will ensure that considerations for streets and local roads will be included in all documents.

327 - Roller-Compacted Concrete Pavements: Killingsworth maintains representation on this committee. ACI 327R-14 Report on Roller-Compacted Concrete Pavements was recently published by ACI. It is intended for this document to replace ACI 325.10R-95: Report on Roller-Compacted Concrete Pavements (Reapproved 2001) at some point in the near future. The committee has also initiated development of an RCC specification for materials and construction to supplement report 327R-14.

329 – Performance Criteria for Ready Mixed Concrete: With the completion of ACI 329R-14, Report on Performance-Based Requirements for Concrete, the committee will focus on developing a "Guide to Writing a Performance-Based Specification." The committee has established several task groups to work on individual chapters. It has also discussed its participation on technical sessions on performance-based specification for the next two ACI conventions. It is also working on a "canned" presentation on performance-based specifications and the content covered in ACI 329R document. Mark Chrzanowski with CH2M Hill has completed his term as chairman of ACI 329. David Tepke with SKA Consulting Engineers, Inc. will serve as chairman for this committee. Colin Lobo (secretary) and Karthik Obla maintains representation on Committee 329.

330 – Parking Lots: The ACI 330 Committee is in the process of completing the ACI 330X "Guide to Design and Construction of Industrial Pavements."  The task group discussed and reviewed committee members’ responses to the Technical Action Committee comments. Amy Miller maintains representation on Committee 330.

ACI 332 – Residential Concrete: Lionel Lemay represents NRMCA on the residential committee. The current focus of the committee is to revise the guide to residential concrete to more closely match the new 2014 residential building code provisions. Lemay, who chairs the subcommittee on materials, production and delivery, revised the section in the guide, balloted and resolved several negatives at this meeting. The guide will be ready to go to TAC by early summer 2015.

365 – Service Life Prediction: This committee is balloting changes to its State of the Art document on Service Life Prediction. NRMCA has provided input. Several sessions are planned at upcoming conventions. Karthik Obla maintains representation on Committee 365.

555 – Recycled Materials: The document "Removal and Reuse of Hardened Concrete" is undergoing revisions and will include discussions on crushed returned concrete aggregates based on research work conducted at the NRMCA Research Laboratory.  The committee continues to organize many technical sessions on the use of recycled materials in concrete at each ACI convention; all of these sessions are very well attended which underscores the importance of this topic. Use of recycled concrete aggregate as unbound base will also be discussed. A survey was presented that showed that out of 40 state highway DOTs, 33 allowed it for that application. AASHTO M319 is a specification for this application. Karthik Obla maintains representation on ACI 555.

560 – Insulating Concrete Forms: The guide to insulating concrete forms is nearly complete and will soon be ready to go to TAC. Lionel Lemay monitors this committee and continues to ballot and protect ready mixed concrete’s interests.

601B - Concrete Quality Technical Manager Certification: ACI has developed a new Concrete Quality Technical Manager (CQTM) certification program.  It is intended that to work as a special inspector at any nuclear facilities construction project, individuals will need to be certified as a CQTM. The program policy has been approved by ACI and this committee will be dissolved and a new committee C 690 will take over this certification.

Lionel Lemay presented during two different technical sessions at the convention, both related to resilience. The first was during the ACI Hot Topic Session on Sunday evening titled Resilience: What Role Will Concrete Play in Making our Communities Safer? which described the NRMCA’s Pathways to Resilience initiative (www.nrmca.org/resilience), including codes and standards advancement and legislative activities. The second presentation was during a session on resilient residential construction titled Tornadoes and Storm Shelters: Update on FEMA Design Guides.