High Tensile Strength Basalt Fiber Chopped Strands for Concrete Crack Control

Basalt Fiber Chopped Strands are high-performance short-cut fibers manufactured from natural volcanic basalt rock, melted at approximately 1450–1500°C and extruded into continuous filaments, which are then precisely cut to specified lengths. Engineered specifically for concrete crack control, these strands serve as an advanced secondary reinforcement material that significantly enhances the toughness, flexibility, tensile strength, and impermeability of concrete and mortar.

As a sustainable alternative to steel fiber, polypropylene (PP), and polyacrylonitrile (PAN) fibers, basalt chopped strands offer superior performance with a significantly lower environmental footprint—100% natural, non-toxic, and produced without harmful additives.

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Key Advantages for Concrete Crack Control

1. Exceptional Crack Bridging & Control
Basalt fibers uniformly distributed in the concrete matrix form a three-dimensional reinforcing network that effectively prevents micro-crack propagation through the “bridging effect”. Studies demonstrate that basalt fibers can reduce early plastic shrinkage cracks by 60–80% and drying shrinkage by 30–50%. At a fiber volume fraction of 0.20%, visible early shrinkage cracks are virtually eliminated.

2. Superior Mechanical Reinforcement

· Flexural strength increases by up to 72.8% (from 5.96 MPa to 10.3 MPa)
· Splitting tensile strength increases by up to 12.28%
· First-crack load increases by up to 40.91%
· Compressive strength increases by up to 23.4%
· Fracture toughness increases by 15.76–17.09%

3. Outstanding Alkali Resistance
Unlike organic fibers that degrade in alkaline environments, basalt fibers maintain ≥75% tensile strength retention in concrete’s high-alkaline environment (pH up to 13), ensuring long-term durability over 50+ years of service life.

4. Excellent Durability Enhancement

· Freeze-thaw resistance: Mass loss after 300 freeze-thaw cycles reduced by 30.4%
· Chloride ion permeability: Reduced by 50.9%
· Impermeability and crack resistance improved by 30–55%
· Fatigue cracking resistance increased by up to 600% in asphalt applications

5. Superior Crack Width Control
Studies confirm that increasing basalt fiber content reduces both crack width and depth, with maximum crack width reduced by up to 54.39%. The fibers slow crack propagation by increasing the energy absorption capacity of concrete.

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How It Works: Crack Control Mechanism

When concrete undergoes shrinkage stress from hydration, temperature changes, or mechanical loading, the uniformly dispersed basalt fibers act as micro-reinforcements that:

1. Bridge micro-cracks at their early stage of formation
2. Transfer stress across crack surfaces, preventing crack widening
3. Delay crack propagation and transform failure patterns from sudden brittle failure to more ductile behavior
4. Reduce pore connectivity and microcrack-pore network formation

SEM (Scanning Electron Microscopy) analysis reveals that basalt fibers effectively restrain microcrack development and reduce microcrack-pore connectivity after freeze-thaw exposure.

General Specifications

Increasing performance of friction material:

Basalt fiber is an eco-friendly, high-performance reinforcement for friction materials (brake pads, clutches), offering superior wear resistance, thermal stability, and low noise compared to asbestos or steel. Its high-temperature resistance and stable friction coefficient make it an ideal, sustainable alternative for enhancing frictional performance and durability in automotive applications.