Charlotte Douglas International Airport CLT - Reconstruction Works with Rapid-Hardening Concrete Concretum® Q-FLASH 2/20 - Project Report

Sep 15, 2026

Uploaded by Asher

Charlotte Douglas International Airport (CLT) used Concretum® Q-FLASH 2/20 rapid-hardening concrete to replace five taxiway slabs totaling 31 yd³ each and to perform a 350 yd² surface replacement. The project ran in July 2023 with air temperatures between 77–86 °F, while concrete was kept workable at 81–86 °F. Delivery, production, transportation, and placement were coordinated to keep curing efficient within an open time of about 60 minutes, supporting night-shift runway operations.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages4

Reading Time10 min

AccessFree to download

Project Overview

Project Facts

Material Delivery and Production

Concrete Specifications

Concrete Performance and Scheduling

Project Report Reconstruction Works with Rapid-Hardening Concrete Concretum® Q-FLASH 2/20 Charlotte Douglas International Airport CLT Taxilane Stands Apron Rapid-hardening concrete: First placement of Concretum® Q-FLASH 2/20 in the USA Project Overview Concretum® Q-FLASH 2/20, the latest generation of rapidhardening concrete, was used for the replacement of 5 slabs, 31 yd³ each, on one of the busiest taxi lanes at CLT. The 5 slabs will prove Concretum® Q-FLASH 2/20’s multi decadelonglifespan and its resistance against high traffic load and aging factors. PROJECT FACTS In this project, the taxilane underwent surface replacement of 350 yd² for enhanced durability and appearance. The prevailing air temperature during the project ranged between 77 to 86 °F, proving the concrete is also workable in tough conditions. The concrete maintained a temperature of 81 to 86 °F throughout its application, promoting effective curing. Notably, the project had an open time of approximately 60 minutes, providing a critical window for executing essential tasks efficiently. Concretum® CEM 100 cement bag delivery MATERIAL DELIVERY AND PRODUCTION The project was executed in July 2023. In total 5 containers containing 96 cement bags of 1000 kg each and 4000 kg of admixtures were shipped to Charlotte in previous months. The cement and admixtures can be handeled and stored like conventional products, ready to be used in a concrete batching plant. For CLT’s slabs replacement the concrete was initially tested and trialed in a concrete plant laboratory nearby the airport. The concrete production and the transportation time lasted around 20 minutes, the concrete remained workable for approximately 60 minutes, enough time to place and finish it. Runway reconstruction with Concretum® Concrete trials before production Metric to imperial system – unit conversion | 1 cm = 0.39 in | 1 m = 3.28 ft | 1 m² = 10.76 ft² | 1 m³ = 1.31 yd³ | 20 °C = 68 ° F | 1 N/mm ² = 1 MPa = 145.04 psi Project Report Charlotte Douglas International Airport CLT Rapid-hardening concrete trial track: 86 °F Concrete temp. 1 hr Workable time 78 yd ³ Concrete per night 515 psi 4 hrs flexural strength 350 yd ² Total surface replaced CLT Airport placement of concrete CONCRETE SPECIFICATIONS | Product | Concretum® Q-FLASH 2/20 | | --- | --- | | Exposure class | XC4, XD3, XF4 | | Strength class | C50/60 | | Consistency | Slump 6 inches to 9 inches | | Max . aggregate size | 1 inch, crushed | | CONCRETE PROPERTIES | | | Shrinkage ɛSH | ≤ 0.25‰ | | Heat of hydration (NF EN 196-9) | 210 kJ/kg | | Flexural strength 4 h | 515 psi | | Flexural strength 5 h | 540 psi | | Flexural strength 24 h | 990 psi | | Moisture content 3 h after setting | ≤ 4 CM-% | CLT Airport finished slab Concretum® Q-FLASH 2/20 high-early strength concrete was especially developed for time sensitive concrete constructions, while providing decades-long life span. One of its most common uses is the overnight airport concrete pavement replacement. The concrete reaches a compressive strength of 3000 psi in less than 2 hours after concrete production and a flexural strength of 500 psi in less than four hours after production (500 psi is the FFA minimum requirement to reopen the pavement section) . This allows full slab replacement in a night shift, minimizing the disruption to the air traffic. Figure 1: Diagramm of possible effective production output of rapid-hardening concrete Suggested Schedule 11 PM 12 AM 1 AM 2 AM 3 AM 4 AM 5 AM 6 AM | Preparation | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Runway closure by air traffic control | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Excavation

FAQs

What concrete product was used for the CLT reconstruction works?

Concretum® Q-FLASH 2/20 rapid-hardening concrete was used for replacing slabs and performing surface replacement works at Charlotte Douglas International Airport (CLT).

How long was the workable/open time during placement?

The project reported an open time of approximately 60 minutes, enabling efficient placement and finishing under active site conditions.

What was the purpose of the rapid-hardening concrete in this airport schedule?

The mix was selected to achieve early strength quickly so that pavement sections could be reopened after a night shift, minimizing disruption to air traffic.

Sep 15, 2026

Uploaded by Asher