How RockFrac® Generates Over 11,200 PSI (78.5 MPa) Expansive Stress
Upon blending RockFrac NEDA with clean cold water, calcium oxide initiates an exothermic chemical hydration reaction: CaO + H2O -> Ca(OH)2 + 15.2 kcal/mol. The progressive crystalline growth and volumetric expansion of calcium hydroxide crystals generate expansive solid stresses within constrained boreholes surpassing 50 MPa up to 150 MPa (500 to 1500 kg/cm2 / 7,250 to 21,750+ PSI). Because tensile strength is substantially lower than compressive strength (rock tensile strength is 4 to 10 MPa, concrete is 2 to 4 MPa), the induced circumferential tensile stresses rapidly surpass the tensile limit of the surrounding matrix, propagating micro-fissures from borehole wall to borehole wall along the plane of least resistance and culminating in wide structural fracture networks.
High ambient temperature, hot summer demolition, quarries in warm conditions
Moderate spring and autumn applications in open quarries and construction sites
Cool weather, late autumn/early spring conditions, sheltered subterranean excavations
Cold weather and sub-freezing winter operations
All-weather versatile formulation where cracking time (30 min to 24 hours) is controlled by adding specific inhibitor dosage into mixing water
| Physical / Engineering Property | Empirical Specification | Engineering Notes |
|---|---|---|
| Physical State | Powder composed of multi-structured inorganic particles | Solid dry inorganic blend |
| Color | Grayish / Grayish-white (may exhibit blue, green, orange, or yellow tint) | Visual identification |
| Odor | Odorless | No volatile organic odor |
| Specific Gravity | Approximately 3.4 g/cm3 | True density of dry active inorganic compound |
| pH (2 g/L Aqueous Solution) | 12 - 13 | Strongly alkaline upon hydration |
| Water Solubility at 20 deg C | Approximately 1.4 g/L | Measured as calcium hydroxide |
| Boiling Point / Melting Point | Not applicable / None | Inorganic refractory mineral powder |
| Flash Point / Flammability | Non-flammable / Not applicable | Product will not burn, no explosion hazard |
| Hygroscopicity | High hygroscopicity | Rapidly absorbs ambient moisture, converts to Ca(OH)2 |
| Maximum Expansive Stress | 50 to 150+ MPa (500 to 1500+ kg/cm2 / 7,250 to 21,750+ PSI) | Reaches peak pressure within 24 hours of hydration |
| Standard Water Mixing Ratio | 30% by total powder weight (1.45 - 1.7 L per 5 kg bag) | Clean, ice-cold water required |
| Recommended Hole Diameter | 30 to 40 mm (Field general: 30 - 65 mm depending on substrate) | Excessive diameter can cause blowouts; undersized inhibits pressure |
| Rock Tensile Strength Baseline | 4 - 10 MPa | Readily exceeded by expansive pressure |
| Concrete Tensile Strength Baseline | 2 - 4 MPa | Readily exceeded by expansive pressure |
| Packaging Unit | 20 kg (44 lb) carton containing four 5 kg (11 lb) plastic bags | Moisture-proof protected packaging |
| Shelf Life | 2 years | Stored dry under constant temperature in original sealed packaging |