UHPC Construction Essentials: Six Details Determine Project Success or Failure

What should be noted in UHPC construction? This is a key question that construction parties must clarify before entering the site. UHPC's high performance depends on standardized construction operations—any oversight in a single detail can lead to quality problems such as substandard strength, cracking, or leakage. Qinglong Group, with 28 years of UHPC construction experience and participation in developing industry standards, has summarized six core construction points to help construction parties avoid risks and ensure project quality; this is also the key to the successful delivery of many of Qinglong's benchmark projects (such as the Shanghai Astronomy Museum and the Yangshengtang Pharmaceutical Hangzhou Industrial Park).

#Material Storage: Moisture-Proof and Sun-Proof, Strictly Control Shelf Life The storage conditions of UHPC materials directly affect construction quality and must be strictly controlled. Qinglong requires raw materials (cement, quartz sand, steel fibers, etc.) to be stored separately in dry, ventilated, sun-shaded warehouses, elevated more than 30cm above the ground to prevent moisture absorption and caking; steel fibers must be stored sealed to avoid rusting that would impair their reinforcing effect. At the same time, material shelf life must be strictly controlled: cement for no more than 3 months and steel fibers for no more than 6 months; expired materials are strictly prohibited from use. Before construction, raw materials must be re-inspected to ensure performance indicators meet requirements, such as the strength of cement and the tensile strength of steel fibers. Qinglong provides test reports for every batch of raw materials, which construction parties can verify on site.

#Mixing Process: Precise Proportioning, Thorough Mixing Mixing is the core step of UHPC construction, requiring precise proportioning and thorough mixing. First, batch materials strictly according to the mix ratio provided by the manufacturer, using electronic measuring equipment with a batching error of ≤±1%; arbitrarily increasing or decreasing water is strictly prohibited (the water-binder ratio is a key indicator affecting UHPC performance). Second, control the mixing sequence and time: first mix the dry materials such as cement, quartz sand, and reactive powders for 1-2 minutes, then add the steel fibers and mix for 2-3 minutes, and finally add the mixing water and mix for 3-5 minutes, ensuring the steel fibers are evenly distributed with no clumping. Qinglong uses automated mixing equipment with real-time monitoring of mixing parameters to avoid the errors of manual mixing; for on-site mixing projects, technical personnel are dispatched to provide on-site guidance to ensure standardized mixing procedures.

#Casting and Forming: Dense Vibration, Avoid Defects The casting and forming stage must ensure components are dense, free of defects such as air bubbles, honeycombing, and rough surfaces. Before casting, debris inside the mold must be cleaned out and a dedicated release agent applied to ensure smooth demolding; during casting, use layered casting with each layer no thicker than 50mm, and vibrate with a high-frequency vibrator, controlling vibration time at 20-30 seconds per point, vibrating until the surface shows paste and no obvious air bubbles escape, avoiding under-vibration or over-vibration (over-vibration may cause steel fibers to float upward). For components with complex shapes or openwork, vacuum-assisted casting or pressure casting technology is used. In the construction of translucent components for the Century Plaza on Nanjing East Road at Shanghai New World, Qinglong used vacuum-assisted casting technology to ensure the density of the concrete around the light guide rods, preventing air bubbles from affecting the light transmission effect.

#Curing Management: Controllable Temperature and Humidity, Ensuring Strength Curing is key to UHPC strength development and requires strict control of temperature and humidity. After casting, perform moisture-retention curing within 24 hours (covering with geotextile, spraying curing agents, etc.) to avoid surface water loss and cracking; afterwards, carry out steam curing or standard curing as needed, with steam curing temperature controlled at 60-90°C for no less than 48 hours, and standard curing for no less than 28 days. Qinglong provides a dedicated curing plan for each project, equipped with professional curing equipment, and monitors the temperature and humidity of the curing environment in real time to ensure stable strength development. During curing, disturbing the components is strictly prohibited to avoid affecting structural integrity.

#Installation Precision: Accurate Positioning, Secure Connection The installation of UHPC components must ensure precision and firmness to avoid later deformation or detachment. Before installation, use 3D laser scanning technology to locate the installation datum lines, ensuring installation error of ≤±2mm; during installation, construct strictly according to the anchoring methods required by the design (such as dry hanging, welding, bolt connection, etc.) to ensure secure connections. Qinglong's construction team conducts pull-out tests on anchor bolts, with pull-out force ≥1.2 times the design value. After installation, promptly treat the joints and fill them with dedicated sealant to ensure waterproof performance. For the installation of large components, a modular hoisting plan is adopted with professional hoisting equipment to ensure construction safety and precision; for example, the UHPC sculptures over 3 meters at the Shanghai Astronomy Museum were successfully installed through modular hoisting.

#Safety Protection: Standardized Operations, Risk Prevention UHPC construction requires attention to safety protection to avoid safety accidents. Construction personnel must wear protective equipment such as safety helmets, protective gloves, and non-slip shoes; for work at heights, safety protection frames must be erected and safety harnesses fastened; equipment such as mixers and vibrators must be regularly inspected and maintained to ensure normal operation; warning signs must be set up on site, construction areas delineated, and unrelated personnel prohibited from entering. Qinglong's construction team strictly complies with safety operation procedures and conducts regular safety training and emergency drills to ensure the entire construction process proceeds safely and without accidents.

The success or failure of UHPC construction lies in the details; the six core points are interlinked and none can be omitted. Leveraging 28 years of construction experience, Qinglong Group has standardized and systematized the operations of each step, helping construction parties avoid risks and ensure project quality through professional technical guidance and on-site control. For construction parties, as long as they strictly follow the specification requirements and with the support of a professional manufacturer, they can successfully complete UHPC construction and deliver high-quality premium projects.