HLY-TS-03: Steam Curing Thermal Shocks, Crazing Cracks & Strength Retrogression Fixes

Fault 1: Spiderweb Crazing Cracks on Pipe Surfaces Post-Curing

Root Causes:

1. Pre-steaming delay too short; pore water flashes to steam prior to initial set;
2. Superheated dry steam baked moisture out of fresh concrete.

Corrective Actions:

1. Enforce strict 2.0-hour preset delay before injecting steam;
2. Install de-superheating atomizers on manifolds to ensure $\ge$ 95% saturation.

Fault 2: 28-Day Strength Retrogression (Under-strength Concrete)

Root Causes:

1. Soaking temperatures sustained in excess of 80°C–85°C;
2. High thermal kinetic shock produces coarse hydration crystals that choke ongoing hydration.

Corrective Actions:

1. Lower soaking ceiling to 65°C–72°C;
2. Install automated thermostatic solenoid cutoff valves.

Fault 3: Circumferential Joint Cracks on Pipe Ends

Root Causes: Quench shock from cooling rate $>25$°C/h or cold wind gusts upon mold opening.

Corrective Actions: Limit cooling rate to $\le$ 15°C/h; verify temperature differential $\le$ 20°C prior to opening.