A high-performance cement modifier for ordinary Portland cement systems. It replaces traditional special rapid-hardening cement outright, delivering fast setting, rapid hardening, high early strength and strength enhancement in one powder —and it lets you dial the demoulding and traffic-opening window to suit the line.
Why it matters commercially: special rapid-hardening cement is expensive and awkward to source. This additive gets you the same behaviour on the 42.5 / 52.5 OPC you already buy, and the late-age strength curve is better than a sulphoaluminate system.
YJ-51YYLX is a high-performance chemical modifier for cement, developed in-house. It is designed to work with ordinary Portland cement systems and to take the place of traditional special rapid-hardening cement, combining fast setting, rapid hardening, high early strength and strength enhancement in a single addition.
The result is an efficient hardening solution for precast component production, specialty cement products and emergency leak-sealing work. Because the hydration control technology lets you adjust the demoulding and traffic-opening window, production turnover rises sharply and total project cost comes down.
Mixed into ordinary Portland cement, YJ-51YYLX breaks through the induction dormancy stage of tricalcium silicate crystallisation and accelerates ionic electrolysis, rapidly generating calcium silicate hydrate (C-S-H) crystals. At the same time it catalyses the hydration of dicalcium silicate, quickly forming ettringite crystals.
Together these drive rapid crystalline hardening of the cement mineral phases, establishing a high-strength hardened matrix within a short cycle —which is what produces the controlled fast set and rapid hardening you see on the line.
Used wherever industrial production and construction impose strict demands on cement hardening speed and mechanical strength:
Demoulding time is adjustable anywhere from 20 minutes to 2 hours, which is usually where the throughput gain in a precast plant comes from.
Co-hydrating with the cement system means early strength builds fast and late strength continues to rise —no retrogression risk.
Effectively suppresses carbonation of the finished product, extending long-term service life.
Controlled micro-expansion relieves shrinkage and cracking risk as mortars and cast products harden.
Pairs directly with ordinary Portland cement, replacing high-priced special rapid-hardening cement.
Adjusting the dose rate controls set speed, early strength and the demoulding window to match each job.
Simpler procurement, fewer trial batches, and no premium paid for special cement.
| Test item | Specification | Measured result |
|---|---|---|
| Appearance | Off-white powder | Off-white powder —pass |
| pH value | > 10 | 10.5 |
| Initial setting time | ≤ 15 min | 9 min |
| Final setting time | ≤ 2 h | 30 min |
| Compressive strength, 24 h | ≥ 25 MPa | 30 MPa |
| Flexural strength, 24 h | ≥ 5 MPa | 5.5 MPa |
| Bond strength | ≥ 1.5 MPa | 1.8 MPa |
Test conclusion: product conforms to specification. Data comes from our own laboratory — actual performance will vary with cement brand, aggregate and ambient temperature, so a compatibility trial is mandatory before production.
Recommended dose: 8%—5% by weight of cement. The higher the dose, the faster the set and the higher the early strength. It can replace part of the cement on an equal-weight basis.
Every mix proportion must be validated by laboratory trial before it goes into volume production. Set time, open time and mechanical performance all need to be confirmed on your own materials first.
Below 10 °C ambient, preheat the cement to 40—0 °C to speed up overall hydration and protect hardening efficiency in cold conditions.
Complete a laboratory small-batch trial before formal production or site work, confirming set cycle, open time and mechanical performance before any batch work begins.
25 kg bags / 1000 kg bulk bags.
No. The product is designed around ordinary Portland cement —42.5 or 52.5 grade —and replaces special rapid-hardening cement in the formulation.
Anywhere from 20 minutes to 2 hours, set by the dose rate. Higher dose means faster set and higher early strength.
No. The additive co-hydrates with the cement system, so late-age strength continues to rise. Late strength performance is better than a sulphoaluminate cement system.
Below 10 °C, preheat the cement to 40—0 °C. Dose may also need raising —we will advise based on your workshop temperature.
Yes. A 25 kg trial sample is available so you can verify set time, strength and workability on your own line.
Send us your cement grade and what you are casting. We will tell you which YJ product applies —or tell you if none of them do.