Worker feeding Voidspan PHL grout into a column base

VoidSpan CG70 Fine Grout being fed into a column base at the
National Arboretum for the Smithsonian.

Compatibility through Traditional Materials

VoidSpan Pozzolanic Hydraulic Lime Grouts and Binders contain a blended hydraulic binder and sand, with less than 2% chemical admixtures by weight.

Our formulations contain lime, pozzolan and, in our PHLc products, a very small amount of cement. By combining the forgiving properties of lime with the more rapid, airless cure of a hydraulic binder, we have created more breathable, “softer” materials that are compatible with historic masonry structures, while meeting the logistical demands of today.

Our careful, quantity-controlled blending of lime and pozzolan in just the right proportion allows for complete reaction of the lime, without the residuals that can bleed out of the masonry and cause streaking in non-hydraulic lime applications.

VoidSpan Pozzolanic Hydraulic Lime Grouts and Binders contain no significant chlorides or corrosive materials. The ultra-low 0.06% shrinkage is achieved without the use of chemical shrinkage compensators, which can sometimes cause damage when in contact with embedded metal elements.

High Durability, Breathability and Adhesive Properties

VoidSpan Pozzolanic Hydraulic Lime Grouts and Binders are extremely frost-resistant. For example, in laboratory freeze-thaw tests our PHLc has repeatedly outlasted traditional mortar formulations, with freeze-thaw resistance approaching that of Indiana limestone.

Our grouts are more breathable than most cementitious grouts and within close range of most late 19th- century and early-to-mid 20th -century mortars.

Our grouts are also more adhesive than cohesive, with a tenacious bond to substrate materials. The intent is to accommodate forced movements sacrificially, rather than through de-bonding or causing damage to the substrate.

Structural Predictability

Even with their lower, more compatible strengths, VoidSpan Hydraulic Lime Grouts are structurally stable and predictable materials. VoidSpan PHLc can be used as a combination void filler and structural adhesive on large-scale applications, and is specifically formulated to support daily three-foot grout lifts with limited bracing. The first three-foot lift is able to support its own weight plus two fluid three-foot lifts above it within two days. VoidSpan PHLc70 has similar mechanical properties but is specifically formulated for smaller scale applications.

Simple to Mix, Easy to Use

VoidSpan PHLc comes in 50-lb. bags or in recyclable 5-gallon plastic pails, each to be mixed with one gallon of water. It also comes in 3,000lb “Super-sacks”.

VoidSpan PHLc70 comes in 1 and 5 gallon containers to be mixed with 1 part water for 5 to 5.5 parts PHLc70 by volume.

Our grouts are very flowable products that can be placed by gravity feeding, pumping and cylinder injection. They can travel relatively long distances in properly prepared and contained cavities and narrow cracks.

Chemical and Physical Grout Properties (PHLc)

Cement Content by weight of Binder: < 15% meeting ASTM C1707 as a “PHLc”
Chloride Content by weight of Binder: 0.008%
Flowability: “Flowable” (135%) per ASTM C230
Dimension Change after Hardening: 0.06% per ASTM C1090
Standard Curing Time (CT): 120-days per ASTM C1713
Water Vapor Transmission: 1.9 g water/sq meter/hour
Compressive Strength: >100 psi at 2 days (Poisson distortion)
550 psi at 7 days (fracture)
1350 psi at 28 days (fracture)
1870 psi at 120 days (fracture)