The ACI Spring Convention was held in Mid-April in Milwaukee. NRMCA staff filed this report on the numerous activities that involved ready mix concrete interests.

130 – Sustainability Committee - The Materials Chapter will be issued as a separate document by ACI 130. This document was sent for review by the Technical Activities Committee. Several chapters for the ACI 130 document on sustainability will be completed over the summer.  These include climate change and resilience, end of use phase, introduction and conclusion.  An inclusive glossary should also be completed in 2016.

132 – Responsibilities Committee - The committee is working on adding a section on responsibilities for repair of concrete construction in its document 132R. The committee also discussed responsibilities related to testing at the jobsite between the contractor and the testing agency, related to access, space, power, initial curing and care of test specimens. It will develop a brief tech note on this topic in concert with statements in other ACI documents. NRMCA will assist with this note. Colin Lobo maintains representation on ACI 132.

201 – Durability - The committee is close to completing a revised 201.2R Guide to Durable Concrete. A Task Group (TG) is working on a tech note for case studies and recommendations for physical salt attack. Other TGs are working on tech notes on deicers and iron sulfides. A TG was created to develop requirements based on formation factor in lieu of w/cm for freeze-thaw resistance and make recommendations to ACI 318. Future technical sessions being organized by the committee include Sulfate Attack; Electrical Methods to Evaluate Mass Transport. Karthik Obla maintains representation on ACI 201.  

211 – Mixture Proportioning - The committee has completed several documents recently: Proportioning with Ground Limestone and Mineral Fillers; Guide to Troubleshooting Concrete Mixtures and Guide for Selecting Proportions for Pumpable Concrete. Task groups are developing guidance on 3-point curves for trial batches and a tech note on proportioning with alternative cementitious materials. The committee continues its work on revising the primary 211 document on proportioning concrete mixtures. Karthik Obla maintains representation on ACI 211.  

214 – Strength Tests - The committee voted on tech notes on two topics - strengths of cubes vs cylinders and use of two 4x8 in. concrete cylinders instead of three for acceptance. Karthik Obla is an associate member.  

232 – Fly Ash - The committee is close to completing a revised document ACI 232.2R, Use of Fly Ash in Concrete. The committee organized two sessions to honor Tarun Naik for his contributions. Karthik Obla is the vice chairman of this committee. 

234 – Silica Fume - The committee continues to work on revisions to its document on guidance with the use of silica fume. In the revision, chapters will self-consolidating concrete and sustainability chapter. 

 

240 - Natural Pozzolans - This new committee on natural pozzolans voted to expand its scope and report on other supplementary cementitious materials like ground glass, rice hull ash etc. that do not fit the definition of natural pozzolans. Karthik Obla maintains representation on ACI 240.

301 – Specifications for Structural Concrete - ACI 301-16 has been completed and should be available in about two months. The revised specification has made some important revisions that move it more toward performance and is consistent with the requirements in the ACI 318-14 Building Code. The old committee has been disbanded. The committee held two sessions outlining the changes in each section of the specification.

 

A new ACI committee has been constituted with new representation while retaining much of the old membership. Subcommittee representation has been strengthened to address issues in the pertinent section with appropriate expertise. The new committee is chaired by Michelle Wilson with the Portland Cement Association. The committee has identified about 200 items of new business that resulted from previous reviews as it was finalizing its specification that could not be addressed due to time constraints. Colin Lobo continues to maintain representation on the new committee.

318 – Building Code for Structural Concrete - The code 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 have change proposals on the following: clarifying acceptance requirements for strength; remove reference to ACI 301 for proportioning concrete; requiring testing technicians to be certified; permitting the calculation of chlorides in lieu of testing to document conformance to chloride limits; adding provisions for alkali silica reactions; revising the number of cylinders for strength tests for 4 x 8 inch specimens from 3 to 2; and clarifying that water and admixtures do not have limits on chlorides. The subcommittee is also working on code change proposals for consideration of performance-based alternatives to w/cm ratio, consideration of elastic modulus of high strength concrete by tests on the proposed mixture; revising the inspection provisions for concrete to be consistent with the International Building Code; defining the lambda-factor for design with lightweight concrete based on equilibrium density; and alternative options for sulfate resistance. One item approved makes the requirements for testing cores consistent with ASTM C42. The committee is also undertaking a thorough review of the requirements in Chapter 26 that needs to be included in specifications. Colin Lobo maintains representation on ACI 318 and ACI Subcommittee 318A.

325 – Concrete Pavements - The committee currently has six documents under development or revision. 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 NRMCA's Brian Killingsworth. Revisions to this document will be completed this summer and balloted in the winter. The committee is 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 will be published by ACI. A revision is underway of ACI 325.11R, Accelerated Techniques for Concrete Paving. Work is complete and will be ready for TAC review in the coming 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. He maintains representation on ACI 325.

327 - Roller-Compacted Concrete Pavements - ACI 327R-14, Report on Roller-Compacted Concrete Pavements was published last year by ACI. It is intended for this document to eventually replace ACI 325.10R-95: Report on Roller-Compacted Concrete Pavements (Reapproved 2001). The committee has also initiated development of an RCC specification for materials and construction to supplement report 327R-14. Brian Killingsworth maintains representation on ACI 327.

329 – Performance Criteria for Ready Mixed Concrete - The committee’s primary objective is to develop a Guide to Writing a Performance-Based Specification. An outline has been developed and task groups have been assigned to develop the chapters. The MasterSpec format will be used for this document so that it can be effectively used by practicing engineers. The committee is completing a presentation that discusses the goal of performance-based specifications and the content of its guide report, ACI 329R-14. The presentation can be used in local presentations by committee members and as an e-learning product from ACI. The committee also agreed to use the NRMCA Specification in Practice topics to develop brief tech notes from ACI 329. These address unnecessary prescriptive requirements in specifications. The committee will sponsor a session on case studies (chaired by Karthik Obla) at a future ACI convention. Colin Lobo (secretary) and Karthik Obla maintain representation on Committee 329.

330 – Parking Lots - The ACI 330 Committee has completed the process of addressing review comments and will soon publish ACI 330X, Guide to Design and Construction of Industrial Pavements. Amanda Hult represents NRMCA on Committee 330.

ACI 332 – Residential Concrete - The Residential Code Requirements for Structure Concrete (ACI 332-14) and Commentary was reviewed and will be revised as necessary prior to Fall 2016 meeting. Amanda Hult maintains representation on ACI 332.

365 – Service Life Prediction - This committee is balloting changes to its state-of-the-art document on Service Life Prediction. Karthik Obla is an associate member of this committee.

522 – Pervious Concrete - The committee is working through revisions to the 522R document and the specification which included discussion of verbiage for mixture proportioning for pervious concrete.  A task group was formed to draft a separate proportioning document. Amanda Hult maintains representation on ACI 522.

555 – Recycled Materials - The document Removal and Reuse of Hardened Concrete is being revised and will include a section on crushed concrete aggregates from returned concrete based on research work conducted at the NRMCA Research Laboratory. Use of recycled concrete aggregate as unbound base will also be discussed. A new chapter on case studies has been included. The committee continues to organize many technical sessions at ACI conventions on the use of recycled materials in concrete due to the continued interest on these topics. Karthik Obla maintains representation in ACI 555.

601B - Concrete Quality Technical Manager Certification - ACI has developed a new Concrete Quality Technical Manager (CQTM) certification program. Additional requirements for an ASME Level III concrete Inspector have been added. The program has been launched and, as a result, this committee is dissolved and a new Committee C 690 has taken over this certification from ACI Spring 2016 convention.

C601-0E Concrete Construction Sustainability Accessor - The Sustainability Accessor certification should be ready for beta testing in Fall 2016. The certification program covers multiple areas of sustainability, including materials, LCA, LCCA, climate change and resilience. The course has been approved by staff.

S801-Eco-Concrete Student Competition - A new student competition is being completed for ACI by members of ACI 130. The course will include LCAs and LCCA on materials and construction.

Technical Sessions - The 123 Forum session (a panel discussion) covered the topic of performance-based specifications. Karthik Obla presented the advantages of performance-based specifications and how they can be implemented. There were five other speakers from FHWA, state DOT, academia and consulting. Panelists and attendees support performance specifications with discussions on the details as it evolves.

 

The hot topic session was on meeting market demand of fly ash. It was noted that nearly 1.5 billion tons of fly ash exists in landfills and ash ponds. If some of this is processed for use, it will address demand. Ponded ash is being processed for beneficial use in concrete in the Carolinas.

 

Technical sessions covered the topic of alkali silica reactions and test methods, use and application of slag cement, and performance approaches to design and construction of mass concrete members.