FAQ#1: How much area will a 44lbs box of Dexpan® fill?
A standard 44lb. Box of Dexpan® would cover approximately 34-36 linear feet.
FAQ#2: How big or small can I drill my holes?
For best demolition results it is recommended to use a 1½&#; Diameter hole (1-1/2 inch).
It is not recommended to exceed 2½&#; or go less then 1&#; in diameter.
FAQ#3: How far apart can I space my holes?
Recommended spacing is as follows:
Depending on the density of the rock / concrete will determine the hole spacing. If you are working with reinforced concrete, it is highly recommended to use 1 foot centers. In most kinds of rock, Dexpan® has been known to range in spacing up to 2 feet! It is recommended to test out the density of your stone first by drilling holes starting at 12&#;, then to 16&#; then to 18&#; then to 24&#; then determine what will work best for your stone.
Depending on your hole size will also determine your spacing. Using a 1½ diameter hole we recommend that the holes are 12&#; apart in reinforced concrete. Using a 2&#; diameter hole you can extend out to 18&#; &#; 24&#; spacing, once again depending on the density of the stone.
Remember that Dexpan® is a &#;controlled demolition agent&#;, you may cut your stone to your desired size, by just making sure that your lines are set on 1 foot spacing.
FAQ#4: How do I determine what type of Dexpan® to use?
Determine the type to use by checking the Rock / Concrete temperature.
(Dexpan III: 23º-50ºF, Dexpan II: 50º-77º, Dexpan I: 77º-104ºF)
FAQ#5: When is the best time to apply Dexpan®?
Best time to apply Dexpan® would be early in the morning, especially in extremely hot temperatures.
For night application, please consult our technical dept.
FAQ#6: What causes the Dexpan® to blow out?
You may get a blow out if there is no expansive space. Or the holes are spaced too far apart.
You can get a blow out if you do your application in the middle of the day when the temperature is at its highest.
You may also experience blow outs if you hole diameter exceeds recommended hole diameter.
You may also experience blow outs if using core drill bits. Note: There has been much success using core bits, this is just a possibility.
Due to the highly alkaline nature of the product:
&#; risk of serious eye damage
&#; may cause skin irritation if left on skin
&#; inhalation of dust may irritate respiratory system or lungs
ALWAYS:
&#; use personal protective equipment:
safety goggles rubber gloves
dust-proof mask proper clothing
&#; Select correct Dexpan product type given material temperature
&#; Ensure adequate ventilation in confined spaces
&#; Mix promptly ensuring mixture is poured into holes within 5 - 10 minutes of combining powder & water
&#; Start with an empty bucket (do not add 2nd bag to any left-over mixture)
&#; Cover filled holes with a tarp
NEVER:
&#; look or stand over filled holes
&#; pour mixture into hot holes
&#; use warm water for mixing
&#; leave excess product sitting in bucket
&#; use glass or enclosed cans to mix/pour Dexpan (could lead to a blow-out with glass or metal fragments)
Factors affecting the timing for cracks to appear include:
&#; material temperature
&#; material hardness
&#; reinforcing present
&#; available expansion space
&#; number and spacing of drilled holes
&#; depth and diameter of drilled holes
&#; temperature fluctuations (material, ambient)
Warm & Hot Conditions
Small cracks can begin to appear as early as 12 hours, but waiting for 24, 36 or 48 hours will result in more extensive and wider cracks.
Cool & Cold Conditions
Expansion and cracking is slower. Depending upon conditions and factors listed above, it may take 36 hours and up to 4 days for optimal expansion and cracking.
1. Not reading the instructions fully.
2. Using the wrong product for the conditions. Choose the version of Dexpan based on the core temperature of the material (concrete, rock) you want to break, not the air temperature.
3. Not taking into account Dexpan requires and open face or expansion room to crack, expand and break apart.
4. Not drilling proper diameter holes. We highly recommend 1-1/2&#; holes to ensure sufficient volume of mixture in the hole to generate required expansive pressure.
5. Taking too long between mixing the Dexpan with water and pouring into the drilled holes. Fill holes within 5 to 10 minutes.
6. Filling holes without consideration of open face or expansion room. Fill row of holes closest to the open face first, then the row behind.
7. Using on materials that are less than 7&#; thick.
8. Drilling completely through a material so that the bottom of the hole is not fully enclosed.
9. Drilling holes at irregular depths. Dexpan is most effective when adjoining drilled holes are equal depth allowing them to work &#;together.&#;
10. Impatience. Give Dexpan a full 24 to 48 hours to achieve fuller expansion, wider cracking.
No. For Dexpan to be effective, we strongly recommend materials to be cracked be a MINIMUM of 8" in depth.
Drill & carbide bit to create holes
Mixing bucket
Electric hand drill with mixing paddle
1.5 L of clean cool water per bag of Dexpan
Safety goggles
Rubber gloves
Dust-proof mask
Proper clothing
Funnel (optional)
For Dexpan to be effective, the material needs an open face or room to expand and break apart. Breaking rock or concrete enclosed on all sides does not allow room for expansive pressure created by Dexpan to crack and break the material.
A well-designed hole-drilling pattern will:
&#; improve effectiveness of Dexpan
&#; save money in quantity of Dexpan consumed
&#; reduces labour by reducing time spent drilling/filling holes
&#; reduces labour cost by pre-cracking difficult materials making demolition and removal easier
&#; allows for more targeted and controlled breaking
&#; gets the job done right, the first time
&#; protects any sensitive surrounding structures
There are a number of alternatives to create the necessary expansion space:
&#; dig around or remove soil tightly enclosing rock or boulders to be cracked
&#; drill a series of empty relief or perimeter holes
&#; in a concrete slab, employ holes drilled at 45° angle (to direct expansion upwards) in the centre of the slab
Spacing, depth and drill pattern should be adjusted based on:
&#; project objectives (demo, dimension, pre-crack)
&#; material density
&#; presence of reinforcing
&#; desired size of broken material
&#; desired cracking time
> if you need to protect an adjoining structure
If you are looking for more details, kindly visit Sanqiang Building Material.
Reinforced Hard Soft
Concrete Rock Rock Concrete Boulders
Diameter 1.5&#; 1.5&#; 1.5&#; 1.5&#; 1.5&#;
Spacing 10 - 12&#; 10 - 12&#; 10&#; 10 - 12&#; 10&#;
Depth 90% 105% 105% 80% 75%
Depending upon the material, project objectives and hole diameter, it is sometimes possible to space holes 12 to 16" apart.
Holes drilled, but not filled with Dexpan mixture can:
&#; create expansion room for material to break apart when the case is enclosed or confined
&#; direct and control cracking
&#; reduce amount of Dexpan required
&#; shorten time for breaking to occur
&#; control breaking to protect part of a structure
&#; direct fracturing
> create corners when creating openings or quarrying stone
More holes spaced closer together results in:
&#; faster break times
&#; smaller more manageable pieces
&#; adds labour cost (drilling & filling more holes)
&#; may increase quantity of Dexpan used
For best results, we highly recommend 1.5" diameter holes.
Do not exceed 2&#; or go less than 1&#; in diameter.
Using smaller diameter holes will require holes to be spaced closer together and may NOT be successful in some materials.
Depending on the density of the material and/or reinforcing present:
2&#; Diameter Holes
You may be able to space holes 12&#; to 18&#; apart
1" Diameter Holes (smaller than we recommend)
You may need to drill the holes 4 - 8" apart. 1&#; diameter holes may be ineffective in some materials.
The best time to pour Dexpan is when the material temperature is coldest and material can gradually warm as the day progresses.
An effective strategy is to drill holes the day before so you can pour first thing early the next morning.
Pouring the Dexpan in the morning, when material is coolest, is HIGHLY recommended in extremely hot temperatures.
1. Using wrong version of Dexpan based on the rock or concrete core temperature.
2. Pouring grout mixture into warm or hot holes.
3. Hole diameter is too large.
4. Hole depth is too shallow. Drill holes to a minimum depth of 5 times the hole diameter.
5. Distance between holes is too large.
6. No open face or expansion room for material to expand, crack and break apart.
7. Mixing more than 1 bag of expansive grout at a time resulting in #9 below.
8. Mixing expansive grout by hand vs. using electric hand drill with mixing paddle attachment resulting in #9 below.
9. Too much time passing between beginning to mix and pouring into holes. Pour Dexpan mixture into holes within 5-10 minutes.
10. Adding expansive grout and water to a bucket with leftover mixture remaining from previously mixed batch.
11. Too much dust in holes.
12. Not measuring water. Using too little water.
13. Using warm water. In warm conditions it is crucial to use cold or ice water.
14. Dexpan boxes sitting in sunlight or warm conditions before being mixed with water.
15. Filled holes exposed to hot direct sunshine.
16. Filling holes incorrectly. Always fill row of holes closest to your open face first, pouring left to right; next row, back to the start, pour left to right.
IMPORTANT
All brands of expansive demolition grouts are susceptible to blowouts if the wrong product is used or instructions are not followed.
Use the correct version of expansive grout based on your material core temperature.
Never stand directly above or look into filled holes.
Early or warning signs do not always precede blowouts. If filled holes start to smoke or steam, that could be a sign they may be about to blow out. Clear the area of people immediately.
1. Ensure correct type of Dexpan is used (Type 3) and stored at 10 degrees Celsius until ready to use.
2. Drill 1.5" diameter holes at 1 foot spacing (filled with Dexpan). To speed up and assist cracking, drill 1/2 to 3/4" diameter relief/expansion holes in between the filled holes (leave them empty).
3. Ensure water temperature is luke warm (approx 10 degrees Celsius), Caution: Cooler water will delay the cracking and DO NOT overheat the water as this could lead to BLOW OUTS.
4. Fill holes in morning so any natural temperature rise during the day supports the reaction vs pouring in afternoon when the temperature might drop overnight and work against the reaction.
5. After you fill the holes, cover with a tarp to help seal in the heat.
6. In extreme cold weather, time sensitive projects some customers have erected hoarding and used heaters to keep the temperature within the recommended range.
7. PATIENCE. It might take 36 or up to 72+ hours for full cracking in extreme cold conditions. If the Dexpan is still clay-like and firm to the touch, it is still working.
The company is the world’s best Concrete Demolition Powder supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.