Ward R. Malisch Concrete Construction Symposium (Part 1)-Should You Reject the Load of Concrete after 90 Minutes (Recorded presentation)

Should You Reject the Load of Concrete after 90 Minutes (Recorded presentation)

Video Transcription

Video Summary

Dr. Colin Lobel from the National ReadyMix Association discusses the contentious 90-minute time limit for concrete delivery, a standard rooted in historical quality concerns. He highlights the challenges it poses for both producers and contractors, including wasted concrete and logistical inefficiencies. The regulation's waiver option remains underutilized due to potential contract rejections. Lobel suggests updated industry practices and technologies could extend delivery times safely, but these may increase costs. Innovations such as automated slump monitoring and the use of hydration stabilizers show promise for extended delivery, yet a proposal to eliminate the 90-minute limit in ASTM C-94 faces resistance. Criticisms include potential quality impacts and unfair demands on producers. Lobel emphasizes the need for early communication of extended delivery needs to integrate costs effectively and reduce unnecessary waste in concrete supply chains.

Keywords

concrete delivery

90-minute limit

logistical inefficiencies

hydration stabilizers

ASTM C-94