How to Mitigate UHPC Autogenous Shrinkage Through Material Design—Mechanism Analysis and Optimization Strategies

Innovation in building materials has always been the core driving force behind architectural aesthetics and structural safety. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group fully understands the decisive role that material performance optimization plays in engineering quality. This article focuses on the issue of UHPC autogenous shrinkage, analyzes its mitigation mechanisms from a material design perspective, and shares Qinglong's optimization strategies and practical experience in this field.

### Industry Pain Points of UHPC Autogenous Shrinkage and the Key Value of Material Design

Ultra-high performance concrete (UHPC) has become the preferred material for large landmark buildings and bridge projects thanks to its ultra-high strength and excellent durability, but early cracking caused by autogenous shrinkage has long been a technical bottleneck for the industry. Data shows that the autogenous shrinkage rate of UHPC can reach 3-5 times that of ordinary concrete, and improper control will severely compromise structural integrity. As a manufacturer of customized UHPC/GRC/GRG/GRP products, Qinglong integrates autogenous shrinkage control technology into its full-chain service system through material composition optimization and process innovation from the detailed design stage onward, providing clients across China and overseas with integrated solutions from scheme design to after-sales maintenance.

### Analysis of Three Mechanisms by Which Material Design Mitigates UHPC Autogenous Shrinkage

**1. Coordinated Regulation of the Cementitious Material System**
Based on 28 years of material R&D experience, Qinglong's research team has built a ternary system of "cement - mineral admixtures - nanomaterials". By introducing ultra-fine silica fume and metakaolin, particle gradation is optimized to achieve dense packing and reduce the number of capillary pores; meanwhile, nano calcium carbonate is added to accelerate the formation rate of C-S-H gel and lower the peak hydration heat. After adopting this formulation, a municipal bridge project reduced its 3-day autogenous shrinkage rate by 28%, verifying the effectiveness of coordinated material regulation.

**2. Fiber Toughening and Constraint Mechanisms**
As a national high-tech enterprise, Qinglong holds multiple patents in the field of fiber modification. By micro-etching the surface of steel fibers to enhance the bond strength of the interfacial transition zone, the fibers can restrain microcrack propagation through a bridging effect when the matrix generates shrinkage stress. In the Century Plaza renovation project on Nanjing East Road, translucent UHPC components incorporating modified steel fibers at a 0.7% volume dosage successfully kept shrinkage crack width within 0.05mm.

**3. Innovative Application of Internal Curing Technology**
To address UHPC's low water-binder ratio, Qinglong developed an internal curing system based on porous ceramsite. At its production base in Nanning, Guangxi, the pre-absorbed water content of the ceramsite is precisely controlled (5-8%) so that it slowly releases moisture during hydration, compensating for self-desiccation shrinkage. This technology has been applied to the GRC-UHPC composite exterior wall panels of the Dongguan Women and Children's Activity Center; over two years of monitoring, panel flatness deviation has remained within ±2mm.

### Qinglong's Full-Chain Optimization Strategy: Closed-Loop Management from Laboratory to Construction Site

**1. Digital Design and Simulation**
Leveraging a provincial engineering technology center, Qinglong uses BIM technology to build autogenous shrinkage prediction models capable of simulating shrinkage curves under different project environments (temperature, humidity). In a commercial complex project in Shenzhen, pre-adjusting the mix ratio and curing regime shortened the on-site construction period by 15 days.

**2. Intelligent Production Control**
Qinglong's production bases are equipped with fully automatic mixing systems and temperature-humidity control systems, achieving a material mixing uniformity error of ≤1%. RFID chip tracing technology has also been introduced to track the shrinkage performance of every batch of UHPC components, ensuring full product quality traceability.

**3. Dynamic Adaptation of Construction Techniques**
Holding Grade II professional contracting qualifications for building decoration engineering, Qinglong's construction team has innovatively adopted a "segmented casting + gradient curing" technique. In an airport project in Saudi Arabia, controlling the casting temperature (20±2°C) and the steam curing regime enabled UHPC components to reach a 28-day strength of 150MPa, with the autogenous shrinkage rate stabilized at 0.08%.

From mechanism research to engineering practice, Qinglong has always upheld its mission of "creating beautiful architecture", solving the UHPC autogenous shrinkage challenge through material design innovation. As vice-chairman unit of the China GRC Association and a member of the International GRC Association, Qinglong will continue to drive industry standard-setting and collaborate with designers and owners to create more benchmark projects that combine aesthetic value with structural safety. Choose Qinglong, choose UHPC/GRC/GRG/GRP solutions backed by 28 years of full-chain experience, and join us in building a new paradigm for the innovative application of building materials.