NRMCA Attends ACI Spring 2014 Convention, Provides Updates on Committee Activity

The ACI Spring Convention in Reno, NV, was held in late March. Following are updates of some activities that involved NRMCA representation.

NRMCA’s Karthik Obla presented on the topic "How much SCMs do concrete producers use and how can it be increased" in a technical session titled "Hydration of Low Portland Cement Binders: Industry experiences and Needs". Karthik also presented on the topic "Performance Criteria for Preventing Physical Salt Attack on Concrete" based on the NRMCA Lab research at a task group of the Durability Technical Committee.

130 – Sustainability Committee - The committee balloted and resolved most negatives for the materials chapter of the guide to concrete sustainability. NRMCA’s Lionel Lemay worked to develop chapters on production and construction, which has been balloted and finalized. The Concrete Construction Sustainability Assessor program is still being developed. This program would be designed to assess an individual's knowledge of sustainable properties of concrete, including thermal mass, durability, pervious concrete, resilience, rating systems, carbon footprint, life cycle analysis, life cycle costing and other best practices. Lionel Lemay maintains representation on ACI 130.

132 – Responsibilities in Concrete Construction - ACI 132 has completed a document that discusses the responsibilities of all stakeholders on a concrete construction project. The stakeholders include the owner, licensed design professional, general contractor, design builder, subcontractor, specialty engineers and subcontractors (those with some design responsibility), concrete material supplier, testing agency, construction manager and forensic consultant. It discusses associated responsibility with prescriptive and performance specifications. At this meeting, the committee completed its response to comments from TAC and made applicable revisions to the document. The ACI 132 document should be available from ACI later in summer. 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 to the Introduction and Conclusion were resolved. NRMCA has provided input to this document. A Task Group (TG) is working on a tech note for recommendations for physical salt attack. Recent NRMCA research findings were presented to this TG; a new rapid test for physical salt attack is being developed. Karthik Obla maintains representation on ACI 201.  

211 – Mixture Proportioning - A new ACI document is now available on concrete mixture submittals. NRMCA helped update this document which includes examples of prescriptive and performance submittals. Two new documents on mixture adjustments and mixture proportioning with ground limestone powder and mineral fillers have been approved. NRMCA provided input to both documents. A TG 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. Karthik Obla maintains representation on ACI 211.

214 – Strength Tests - This committee is collecting project compressive strength test data to update the table showing the standards of concrete control for both testing variability as well as batch to batch variability. A new future session is planned to discuss 4 x 8 in. and 6 x 12 in. cylinder test results and whether the ACI 318 requirement that three 4x8 in. cylinders constitute a test result (as opposed to only two 6 x 12 in. cylinders) needs to be revised. NRMCA will be participating in this session. Karthik Obla is as an associate member.

232 – Fly Ash and Natural Pozzolans - The committee has successfully balloted revisions to address all the TAC comments on a new report on high volume fly ash (HVFA) concrete and the document is expected to be published soon. The committee voted to disband natural and processed pozzolans into a different committee due to the large number of such materials being increasingly used worldwide. This will allow this committee to focus on issues related to fly ash in concrete. The committee formed a task group to work on a new document "Guide to Specifying Fly Ash for Concrete Performance". The committee is involved in responding to the TAC suggestions on ACI 232.2R, Use of Fly Ash in Concrete. Tom Adams of ACAA reported that EPA has responded that the beneficial use of fly ash in concrete is a safe application. The complete presentation can be obtained by contacting Tom. In the next convention the committee is co-sponsoring two sessions on Improving Early-Age Properties of Concrete with SCM’s. Karthik Obla is the chairman of ACI 232.

301 – Specifications for Structural Concrete - ACI Committee 301 devoted about 20 hours of meeting time resolving issues from previous ballots in various sections of the specifications – concrete materials, construction, precast concrete, post-tensioned concrete, architectural concrete and the general section. The committee also addressed requirements for alkali silica reactions as a new item in ACI 301 and arrived at a consensus on stating requirements. The specification revisions will continue to evolve as resolution to ballots are completed. The committee has received a relatively final version of the reorganized ACI 318 Building Code and will develop needed revisions to ACI 301 to be consistent with ACI 318. ACI 301 is working toward completing its revised specification through the ACI review process (TAC and Public review) by Fall 2015. The Committee follows a schedule of Web conference calls every two weeks to address resolution to ballots and revisions to the specification. Colin Lobo maintains representation on ACI 301.

318 – Building Code for Structural Concrete - ACI Committee 318 has completed the reorganized Code following response to comments from ACI TAC, which resulted in some modest revisions to the document. The reorganized Code will be posted for public review – the last part of the process of completing an ACI standard – sometime in June. Members are encouraged to review and comment on the revised Code. The primary chapters of interest to concrete producers will be Chapter 19 – Concrete: Design and Durability Requirements and Chapter 26 – Construction Documents and Inspection. The Committee will address public comments at a special meeting in August. It is expected that the Code will be available early in Fall 2014 so that it can be referenced in the next version of the International Building Code. ACI Committee 318 will then be disbanded and a new committee will be formed for the next 6-year cycle. The new committee will meet at the ACI Fall Convention in Washington, DC. The new Committee 318 will be chaired by Jack Moehle, UC Berkeley.

There were several presentations by 318 Committee members on the reorganized Code at the ACI Convention and these were well received. Colin Lobo maintains representation on ACI 318.

329 – Performance Criteria for Ready Mixed Concrete - ACI Committee 329 has completed its guide document on performance requirements for concrete materials. The document is based on the ITG-8 report with committee revisions. The document is in the publication process and will be available in summer. The Committee has received approval from ACI TAC to develop a document on "how to write a performance specification". The document is intended to provide some general background and rationale and recommend specification clauses. The Committee decided to follow the sequence used in the MasterSpec format that design engineers are most familiar. The committee has developed an outline and will get consensus before working on developing the document. In parallel, there was some discussion on developing a seminar on the subject that could be offered by ACI. There might be possible funding from FHWA for dissemination part of this effort. Another goal of the committee is to make recommendations to ACI standards committees 301 and 318, suggesting performance-based alternatives to current requirements. Colin Lobo (secretary) and Karthik Obla maintain representation on Committee 329.

330 – Parking Lots - The ACI 330 Committee is completing the ACI 330X "Guide to Design and Construction of Industrial Pavements."  The task group spent considerable time editing all chapters for submission to the Technical Action Committee in preparation for the afternoon Committee meeting. The document will be sent to the Technical Activities Committee (TAC) for review at its summer meeting. The group also spent considerable time discussing threshold differences between the ACI 330 and 330X documents. A subcommittee has been created to offer recommendations to the Committee that will clearly differentiate the basis of utilizing each document. The end of the meeting allowed time for Committee members to discuss interesting projects/issues. Two Committee members discussed the benefit of utilizing the Design Assistance Program (DAP) offered by NRMCA. Amy Miller maintains representation on Committee 330.

ACI 332 – Residential Concrete - After finalizing the 2013 residential code, the committee has turned its focus to updating the guide to residential concrete in order to match the code. The process should be completed in 2014. Lionel Lemay maintains representation on ACI 332 and will chair the subcommittee on materials, production and delivery. Lemay updated the section in the guide and will ballot the section in May 2014.

522 – Pervious Concrete - The 522 Committee is updating the accompanying guide, ACI 522R-08. Several ballots were recently completed with more to come. A considerable focus will be providing guidance on proportioning of pervious concrete mixtures. A number of presentations were given, including one on finishing concrete using a skip float by Dave Mitchell; evaluating reinforcement corrosion in two layered concrete (pervious/conventional) by students under Dr. John Kevern, University of Missouri, and a presentation on paste film-forming used as a parameter for mixture proportioning given by a student at Clemson University. Updates were given by liaisons in associated organizations: American Society of Civil Engineers, NRMCA’s Pervious Subcommittee, ASTM, Pervious Concrete Pavement Association and the Transportation Research Board.  Amy Miller maintains representation on ACI 522.

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 is organizing two technical sessions at the next ACI convention in Washington, DC; a paper on the use of crushed concrete aggregate for internal curing based on research conducted at the NRMCA research laboratory will be presented. Karthik Obla maintains representation on ACI 555.

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 Concrete Construction Special Inspector (CCSI) and CQTM.  The CQTM program measures the technical knowledge of a candidate in regards to mixture proportioning for normal, heavy and lightweight concretes, high strength concrete, durability issues, ingredient materials for concrete, evaluation of strength, CLSM, SCC and pervious concrete, and Building Code requirements related to concrete materials. The text for the exam comprises of the reports of over 20 technical committees. A pilot examination was held in Reno on March 26. The pilot exam comprised of a written and performance exam and lasted a total of 6 hours. About 20 personnel, including NRMCA’s Karthik Obla, took the pilot examination.

For more information, contact Colin Lobo at clobo@nrmca.org or Karthik Obla at kobla@nrmca.org.