Solar Reflectance Index (SRI) paver blocks are engineered to reduce surface heat gain by reflecting more solar energy and releasing absorbed heat efficiently. SRI is a scientifically measured value used globally to evaluate the thermal performance of construction materials exposed to sunlight. Higher SRI values indicate a cooler surface, making these pavers ideal for sustainable urban development, heat-island mitigation, and green-building certified environments.

Why SRI Matters Today

Urban surfaces absorb enormous amounts of solar heat, significantly increasing the ambient temperature of densely built environments. High-SRI paver blocks are one of the most effective solutions to mitigate the urban heat island effect. They improve thermal comfort in outdoor spaces, reduce air-conditioning loads on nearby structures, and support compliance with modern sustainability standards—including green-building certifications and heat-island mitigation credits.

Understanding Solar Reflectance Index (SRI)

Solar Reflectance Index is a composite value derived from two optical properties of a surface:

1. Solar Reflectance

The proportion of solar energy the surface reflects across all wavelengths—including UV, visible, and infrared.

2. Thermal Emittance

The ability of the surface to release absorbed heat back into the atmosphere.

SRI combines these values using the calculation method defined under ASTM E1980. A material with a high SRI value stays significantly cooler under direct sunlight, resulting in improved outdoor comfort and reduced environmental heat accumulation.

How SRI Value is Measured

The formula defined in ASTM E1980 is:

SRI=Tblack−TsurfaceTblack−Twhite\{SRI} = \frac{T_{\{black}} – T_{\{surface}}}{T_{\{black}} – T_{\{white}}}SRI=Tblack​−Twhite​Tblack​−Tsurface​​

Where:

• T_black = theoretical temperature of a standard black surface
  
• T_white = theoretical temperature of a standard white surface
  
• T_surface = steady-state surface temperature of the tested material
  
• All temperatures are expressed in Kelvin (K)
  

Parameters Required

To compute SRI, two characteristics are essential:

1. Solar Reflectance
   
   • Measured according to ASTM E903 or ASTM C1549
     
2. Thermal Emittance
   
   • Measured according to ASTM C1371
     

Both values are inserted into the ASTM E1980 model to compute final SRI.

SRI Colour Performance Chart

Below is a professionally formatted example table (similar to your shared reference) showing typical SRI values for common paving colours. Values may vary depending on mix design, pigment type, and curing method.

Colour	Solar Reflectance (ASTM E903)	Thermal Emittance (ASTM C1371)	SRI (ASTM E1980)
Pure White	0.78	0.85	92
Cream	0.73	0.86	88
Light Ivory	0.68	0.86	83
Ivory	0.63	0.85	75
Light Grey	0.51	0.85	58
Sandstone	0.52	0.86	60
Beige	0.44	0.85	49
Terracotta	0.28	0.86	28
Medium Grey	0.26	0.84	24
Dark Grey	0.14	0.87	10
Charcoal Black	0.11	0.85	6

Technical Advantages of High-SRI Paver Blocks

• Reduced surface heat build-up
  
• Lower surrounding temperature in pedestrian areas
  
• Increased thermal comfort for walkways & pavements
  
• Extended material life due to reduced thermal stress
  
• Assists in meeting green building / heat island credits
  
• Supports sustainable, climate-responsive landscape design

Applications in Modern Construction

SRI paver blocks are widely preferred for commercial, residential, and institutional environments where heat management, sustainability, and pedestrian comfort are critical. They are commonly used in walkways, plazas, parking areas, public courtyards, educational campuses, resorts, rooftop landscapes, and smart-city infrastructure. Their ability to reduce surface temperatures contributes directly to improved micro-climate conditions and long-term energy efficiency around buildings.

A Smart Investment for the Future

Opting for Solar Reflectance Index paver blocks is an investment in sustainability, comfort, and long-term cost efficiency. They contribute to environmental safety, reduce heat stress, and support the creation of modern, climate-adaptive built environments. For developers, architects, builders, and urban planners, SRI paver blocks represent the next step in responsible and forward-thinking construction.

Upgrade to High-SRI Paver Blocks for a Cooler, Smarter Landscape

Enhance your project with technically engineered Solar Reflectance Index (SRI) paver blocks from Velmurugan Paver Blocks. Designed for durability, heat-island reduction, and superior performance, our SRI-tested paving solutions deliver long-term value for commercial, industrial, and urban developments.

Need SRI-certified paving solutions for your site? Contact Velmurugan Paver Blocks today for expert guidance, samples, and quotations.