FDA
FDA 21 CFR 1040.10 - Laser Product Performance Standards
Todd DunningMAUnited States
Optical Materials for Laser SystemsPublished
Dec 16, 2025
Concrete Laser Cleaning
When laser cleaning concrete, begin with controlled beam passes to strip away surface contaminants and restore durability, all while preserving its structural integrity.
Laser-Material Interaction
Absorptivity
0.75
0.6
0.75
0.9
Absorption Coefficient
5e4
m⁻¹
1e4
5e4
1e5
Laser Damage Threshold
8
J/cm²
5
8
15
Thermal Shock Resistance
1.5
MW/m
1
1.5
2
Reflectivity
0.25
0.1
0.25
0.4
Thermal Destruction Point
1,000
K
800
1,000
1,200
Vapor Pressure
10
Pa
1
10
100
Thermal Destruction
773
K
273
773
2,500
Laser Reflectivity
0.35
0.21
0.35
0.33
Thermal Expansion
1.2e-5
K^{-1}
6e-6
1.2e-5
1.2e-5
Thermal Conductivity
1.4
W/m·K
0.08
1.4
2.5
Specific Heat
880
J/(kg·K)
828
880
1,102
Laser Absorption
0.9
0.11
0.9
1.3e5
Thermal Diffusivity
5e-7
m²/s
0
5e-7
1e-6
Ablation Threshold
3.2
J/cm²
0.85
3.2
4.2
Concrete Laser Cleaning Material Characteristics
Fracture Toughness
0.7
MPa m^{1/2}
0.15
0.7
1.1
Density
2,400
kg/m³
682
2,400
3,268
Oxidation Resistance
0.98
0
0.98
1,155
Youngs Modulus
30
GPa
11.4
30
1.2e10
Hardness
0.4
GPa
0.28
0.4
36.7
Compressive Strength
25
MPa
5
25
100
Tensile Strength
3.2
MPa
1
3.2
15
Flexural Strength
4.2
MPa
0.84
4.2
13.1
Corrosion Resistance
300
Ω·m
0.02
300
105
Laser Damage Threshold
4.2
J/cm²
1.1
4.2
8.8
Thermal Destruction
773
K
273
773
2,500
Laser Reflectivity
0.35
0.21
0.35
0.33
Thermal Expansion
1.2e-5
K^{-1}
6e-6
1.2e-5
1.2e-5
Thermal Conductivity
1.4
W/m·K
0.08
1.4
2.5
Specific Heat
880
J/(kg·K)
828
880
1,102
Laser Absorption
0.9
0.11
0.9
1.3e5
Thermal Diffusivity
5e-7
m²/s
0
5e-7
1e-6
Concrete surface magnification
Before Treatment
The surface shows dark stains and fine particles clinging tightly to the rough texture. Cracks and pits fill with debris that scatters light unevenly across the view. Layers of grime obscure the underlying grains completely.
After Treatment
Laser treatment removes the stains and exposes smooth, bare areas on the texture. Particles vanish, leaving clear edges around the grains in the view. The surface now reflects light evenly without any hidden debris.
Regulatory Standards & Compliance
ANSI
ANSI Z136.1 - Safe Use of Lasers
IEC
IEC 60825 - Safety of Laser Products
OSHA
OSHA 29 CFR 1926.95 - Personal Protective Equipment
Concrete Laser Cleaning Laser Cleaning FAQs
Q: Can laser cleaning remove paint and graffiti from concrete without damaging the surface?
A: Preserves substrate avoids aggregate exposure. Yes, laser cleaning pretty effectively removes paint and graffiti from concrete. By employing a 1064 nm wavelength at 2.5 J/cm² fluence, it selectively ablates the coating while preserving the substrate. This approach typically avoids the surface etching and aggregate exposure seen in abrasive methods like sandblasting.
Q: What laser settings (wavelength, power, pulse duration) work best for concrete cleaning?
A: 1064 nm nanosecond pulses. For concrete's heterogeneous makeup, I'd recommend a 1064 nm wavelength at about 100 W average power. Typically, a fluence around 2.5 J/cm² with nanosecond pulses effectively removes contaminants while fairly mitigating thermal stress on the aggregate and cement matrix, preserving substrate integrity.
Q: Does laser cleaning create hazardous dust when used on concrete, and how is it controlled?
A: Minimizes respirable silica dust. Compared to abrasive blasting, laser cleaning produces significantly less respirable silica dust. Typically, with our 100 W, 1064 nm settings, it basically generates coarse debris. Effective fume extraction remains essential to manage the fine particulate produced.
Q: How effective is laser cleaning for removing biological growth like mold or algae from concrete?
A: Surface sterilization prevents regrowth. Laser cleaning pretty effectively removes surface biological growth at ~2.5 J/cm² by thermally denaturing contaminants. It also sterilizes the concrete, typically preventing immediate regrowth. That said, its effect stays fairly limited to the surface, with no penetration for deeply embedded organisms.
Q: Can laser cleaning be used on reinforced concrete without damaging the rebar?
A: Preserves concrete-rebar bond integrity. When properly tuned, laser cleaning at 2.5 J/cm² pretty effectively removes contaminants from reinforced concrete. This approach fairly well preserves the structural cover over rebar, preventing exposure while upholding the vital concrete-rebar bond integrity under optimal parameters.
Q: What is the typical cleaning rate (square meters per hour) for concrete surfaces with laser?
A: 2-8 m²/hour multiple passes. Typically, cleaning rates fall between 2 and 8 m² per hour with a 100 W laser at 1064 nm. Actual speeds depend fairly heavily on contaminant type and surface texture, often requiring multiple passes at 2.5 J/cm² for full removal.
Q: Does laser cleaning alter the surface profile or texture of concrete?
A: Preserves micro-roughness for adhesion. Properly tuned laser cleaning at 2.5 J/cm² basically removes contaminants without altering the concrete's micro-roughness. That 1064 nm wavelength pretty much avoids glazing the aggregate, preserving the surface profile that's essential for optimal coating adhesion.
Q: How does laser cleaning compare to dry ice blasting for concrete restoration projects?
A: Preserves substrate without damage. Laser ablation at 2.5 J/cm² pretty selectively removes contaminants without harming the concrete substrate, unlike dry ice blasting. This delivers a superior, residue-free surface for better coating adhesion, though the upfront equipment cost is fairly higher.
Q: Can laser cleaning remove efflorescence (white salt deposits) from concrete surfaces?
A: Prevents recurrence on porous substrate. Yeah, laser cleaning pretty effectively removes efflorescence by vaporizing surface salts at around 2.5 J/cm². Basically, this beats chemical washes by clearing deposits without adding moisture, which is crucial for stopping their quick return on porous concrete.
Q: What are the limitations of laser cleaning for heavily contaminated or oil-stained concrete?
A: Heavily oil-stained concrete creates a pretty major limitation: the depth of laser interaction. With our standard 2.5 J/cm² fluence, we typically clear surface contaminants well, but deeply penetrated oils often demand multiple passes. This fairly extends process time as the laser ablates contamination layer by layer.
Q: Is laser cleaning safe for historic concrete structures and monuments?
A: Preserves original material integrity. Properly calibrated at about 2.5 J/cm², laser cleaning is fairly safe for historic concrete. This non-contact method offers precise control, typically removing contaminants like soot or biological growth with minimal substrate loss, aligning well with core conservation principles of preserving original material integrity.
Concrete Laser Cleaning Dataset Download
License: Creative Commons BY 4.0 • Free to use with attribution •Learn more
