Is the shrinkage rate of UHPC high? Low shrinkage characteristics and control technology

UHPC has an extremely low shrinkage rate, with a 28-day drying shrinkage of ≤0.03% and creep shrinkage of ≤0.02%, only 1/3 to 1/4 that of ordinary concrete (shrinkage rate 0.08-0.12%). Qinglong effectively controls shrinkage deformation through material mix optimization and curing processes; large components such as those for the Shanghai Astronomy Museum and Shanghai New World Plaza show no shrinkage cracking.

I. Core Shrinkage Indicators and Advantages

Low shrinkage ensures component stability. Drying shrinkage rate: ≤0.03% at 28 days, stabilizing by 56 days with no later shrinkage; creep shrinkage: ≤0.02% under long-term loads, while ordinary concrete reaches 0.05-0.08%; application advantages: suitable for large, super-long, and irregular-shaped components, avoiding shrinkage cracking—Qinglong's large UHPC components (≥6m) have a shrinkage crack incidence rate of 0.

II. Technical Safeguards for Low Shrinkage Properties

Four key technologies suppress shrinkage deformation. Mineral admixture optimization: adding 10-15% silica fume plus 5-8% fly ash reduces cement hydration heat and shrinkage—Qinglong's admixture synergy lowers the shrinkage rate by 40%; fiber restraint: steel fibers and alkali-resistant glass fibers form a three-dimensional network that restrains matrix shrinkage—Qinglong's fiber content is 2-3%, achieving a shrinkage restraint efficiency of 80%; low water-binder ratio design: a water-binder ratio ≤0.35 reduces hydration water demand and drying shrinkage—Qinglong controls the water-binder ratio with ±0.01 precision; curing process optimization: 7 days of curing at constant temperature (20±2℃) and humidity (≥90%), followed by natural curing—Qinglong's curing process further reduces the shrinkage rate by 20%.

III. Qinglong Project Practice and Application Value

Real-world projects verify the reliability of low shrinkage. Shanghai Astronomy Museum public art sculptures: oversized UHPC components over 3 meters, integrally formed with no shrinkage cracks; Shanghai New World Plaza: 12㎡ oversized UHPC wood-grain translucent panels with no shrinkage deformation after assembly and flatness ≤1mm/m; application value: fewer expansion joints, enhanced decorative effect, and lower maintenance costs—Qinglong's low-shrinkage UHPC reduces project maintenance costs by 25%; technical advantages: holds 3 patents related to low shrinkage and participated in formulating the “UHPC Shrinkage Rate Testing Standard”; commitment guarantee: free repair or replacement of components for shrinkage-induced cracking, with shrinkage deformation tracked throughout the warranty period.