Ir Dr Herbert Zheng is a concrete technologist and industry executive with over 30 years of experience in advanced concrete and sustainable construction materials. A PhD graduate of The University of Hong Kong and an alumnus of Tongji University, he has led the development and application of C100 MPa concrete for One Island East, C80 MPa concrete for the Harbour Area Treatment Scheme Stage 2A, and Hong Kong’s first roadwork application of Low-Density Engineered Cementitious Composite (LD-ECC) at Shap Pat Heung Interchange. He has been a member of the American Concrete Institute (ACI) for over 15 years. As CEO of Glorious Concrete (H.K.) Ltd. and Orientfunds Precast Ltd., his work focuses on translating research in advanced, low-density and low-carbon concrete technologies into reliable production and practical engineering applications.

Ir. Dr. Herbert Zheng

Glorious Concrete (H.K.) Ltd. / Orientfunds Precast Ltd., Hong Kong

Abstract

Low-Density Engineered Cementitious Composite (LD-ECC) was developed in Hong Kong to address key technical limitations of conventional lightweight foamed concrete, including brittleness, high water absorption and permeability, cracking, and variability in production quality.

Through engineered mix design, LD-ECC can achieve a density as low as about 650 kg/m³ while exhibiting notable engineering strength, high compressive ductility, high fatigue resistance, good crack control, self-healing capability, good pumpability and near self-compaction. Its post-peak compressive strain reaches approximately 8.8%, which enhances material robustness and its ability to accommodate possible deformation due to ground settlement. Importantly, LD-ECC can be produced and delivered through an established ready-mixed concrete QA/QC system, enabling reliable application in full-scale construction.

At Shap Pat Heung Interchange, the use of LD-ECC enabled a lightweight embankment to replace a conventional reinforced-concrete box structure thereby substantially reducing slope and foundation loading. Its pumpability and notable early-age strength, together with the use of precast concrete panels as permanent formwork, further simplified construction and reduced high-risk and labour-intensive activities.

The project demonstrates how advanced material can enable a fundamental change in infrastructure design and construction. Following the successful application of LD-ECC, CEDD and the Building Technology Research Institute are collaborating to develop technical guidelines to facilitate wider and more optimised use of LD-ECC in future engineering works.