This session objective is to present the content of the new guide on In-Transit Monitoring Systems for Ready-Mix production. The various topic will present element of the document, with an emphasis on case studies. Presentations will mainly focus on will focus on in-drum slump, air content and temperature evaluation. The targeted audience are concrete producers, contractors and owners who might benefit from using these new technologies.
Learning Objectives:
(1) Understand and present the ongoing work and key components of the Guide for On-Board Monitoring and Management Systems of Fresh Concrete Delivery, enabling producers, contractors, and owners to effectively implement and utilize these technologies;
(2) Explore methods to improve quality control in ready-mix concrete, including continuous measurement techniques, and understand their effects on water control, strength management, and material efficiency;
(3) Examine the advantages of using integrated sensor data on ready-mix trucks to enhance operational efficiency, reduce material rejection, and provide more accurate quality control parameters;
(4) Understand the role of high-range water reducers and IoT systems in admixture management during concrete transit, focusing on efficiency improvements, reduced cement usage, and environmental benefits in both commercial and residential applications.
Presentation of the Guide for On-Board Monitoring and Management Systems of Fresh Concrete Delivery
Presented By: Lee Thrasher
Affiliation: CTS Cement
Description: The ready-mixed concrete industry has seen substantial growth and development of mixer truck mounted systems that provide producers with various monitoring and/or management systems for fresh concrete delivery. Wide-spread use and acceptance of these systems created the need for an overall guide document that producers, prospective purchasers, contractors, and specifiers can reference for an understanding of the components, capabilities, limitations, and function of these systems. These advanced systems offer an unprecedented tool for producers which positively impact delivery, quality, and management processes involved in ready-mixed concrete production. ACI Committee 304 – Measuring, Mixing, Transporting, and Placing Concrete is well represented by manufacturers, distributors, and users of this equipment who decided to put together a task group to develop the requested document. This presentation outlines the task group efforts for the document development, recognizes the international extent of contribution and support, and puts forth the committee goals for the intended audience and ready-mixed concrete industry with use and adoption of this guide.
It’s the Quantity, Not the Quality! (OK, Maybe Both)
Presented By: Nathan Tregger
Affiliation: Verifi LLC
Description: Quality control on ready-mix concrete is far behind other industries (e.g. agriculture). In particular, quality control typically involves one measured slump on every five to twenty deliveries, while this one slump is taken either at the plant or at the site from a 0.25 ft3 sample expected to represent up to 10 cubic yards (0.09%!). This presentation focuses on changes that producers and contractors can make together when slump of the delivery is measured every 30 seconds throughout the delivery from batching to discharge. In particular, water control, management and impacts on strength and cement consumption are discussed, demonstrating a large potential for reducing cement through high-quantity, quality control.
Unexpected Advantages of On-Board Monitoring Systems
Presented By: Denis Beaupre
Affiliation: Command Alkon
Description: Position, drum speed, temperature and workability sensors on-board of ready-mix trucks have been around for many years. Air content sensors have recently been added to the ‘’standard’ list of readily available equipment. Each of these sensors provides advantages which, even when taken independently and on real time display, can ease the work of many, including truck drivers, QC engineers and contractors. This presentation will emphasis on the extra advantages that comes when the data from all available sensors are used together and analyzed historically to provide additional information leading to additional parameters (e.g.: fresh concrete homogeneity, rogue water detection, drum emptiness detection, drum build-up and washing detection etc.), more controlled operations, less rejection, time saving and, in the end, great value for the producers and owners. The presentation will also introduce new sensor that can completely change the field QC operation: density sensor can possibly dismiss completely the need to make concrete cylinders.
Improving Sustainable Concrete Production Practices Using an On-Board Monitoring System of the Fresh Concrete Properties
Presented By: Marc Jolin
Affiliation: Laval University
Description: The presentation will focus on the advantages of using on-board sensor system for the delivery of ready-mix concrete. Specifically, it will concentrate on the results of recent research efforts and field evaluation obtained through collaboration with industrial partners. Major findings and new development include new sensors such as air and density sensors and improvement in the use of workability sensor for the detection of homogeneity and evaluation of rheological properties, all without sampling and in a continuous manner during transport.
Accuracy and Variability of Air Content as Measured with In-Drum Sensors and Standard Tests
Presented By: Kenneth Hover
Affiliation: Cornell University
Description: The results of in-drum sensors of any kind are inevitably compared with results of standard tests on fresh concrete, typically performed one time on one sample of fresh concrete per truck (with not all trucks sampled). The presentation begins with a series of studies conducted by the author for the Federal Highway Administration, illustrating the variability of standard tests of fresh concrete performed under field conditions, when multiple tests are performed on multiple samples obtained from one single truck, starting from shortly after arrival to beyond 90 minutes from batching (results of 8 separate test series are reported). Against this background of variability of air content obtained with standard tests, a full-scale field-test program was designed and carried out to compare continuous readings from an in-drum air-content sensor with the results of multiple standard tests of air-content. Eight cubic yards of nominal 4000 psi, air-entrained (6%) concrete were batched from a stationary mixer into a front-discharge ready-mix truck with an 11 CY drum fitted with an acoustic air meter. The truck arrived at the test-site 20 minutes after batching. Concrete was sampled four times over 95 minutes on-site per ASTM C172 with two intermediate discharges of concrete into forms, and two additions of water. At each sampling, ASTM C231 (pressure-meter) and C138 (gravimetric) air tests were conducted by ACI-certified technicians; 4x8 cylinders were cast for compression-strength and hardened-air analysis per ASTM C457. All test equipment was calibrated immediately prior to test. Acoustic air content was monitored continuously throughout the testing program for comparison with results of currently accepted, standard methods. All results are compiled and discussed.
Realizing CO2 Savings Through In-Transit Admix Management
Presented By: Jon Deering
Affiliation: Core Ready Mix
Description: High-range water reducers (HRWRs) have been an enabler of lower cement contents since their introduction late last century. There now exists integrated IoT and hardware systems that allow automatic admixture additions on concrete mixer trucks during transit from batching to pouring at the job site. These systems are programmed to add admixture as slump loss occurs. This method results in two benefits: 1) a delayed addition of admixture, which has been shown to result in a more effective dosage and 2) the admixture is only added when slump loss occurs. This second point means no unnecessary admixture is added during delivery of the concrete. Typically, HRWR’s are used in commercial and high-performance applications (e.g. office buildings, bridges). What will be discussed in this presentation is the adoption of the in-transit admixture management system to demonstrate increased admixture efficiency for residential concrete. Furthermore, the use of admixture in residential applications has allowed a redesigned mixture proportion - leading to significant amount of cement reduction and associated CO2 at the same specified strength.