Futuristic road construction with polymer additive.

Road Warriors: Can This Soil Trick Save Our Streets?

Nico Varela in Tech & Innovation June 2025 • 5 min read.

"Discover how a simple polymer additive could revolutionize road construction and maintenance, making our infrastructure more sustainable and durable."

As State and Federal governments face growing pressure to design, build, and maintain road infrastructure with limited funds, the demand for sustainable and high-performing roads has never been higher. Public expectations are constantly evolving, pushing for environmentally friendly solutions that utilize recycled materials and improve marginal quality resources. This has sparked a surge in innovative construction techniques aimed at leveraging low-quality local materials for road pavement construction.

The development of new techniques is especially important in urban environments, where high-quality aggregates are scarce and costly to transport. Traditional stabilization methods using cementitious additives have proven effective in enhancing pavement performance and extending structural life. However, these methods often require large quantities of additives and lengthy curing times, leading to increased construction time and costs. Furthermore, cementitious additives can increase the risk of reflective cracking in asphalt surfaces.

This has led to a growing interest in non-traditional stabilizers like polymers, which have demonstrated effectiveness in reducing permeability and increasing durability. Polymers offer the added benefit of being less time-dependent during mixing and compaction and more environmentally sustainable. One such polymer, polyacrylamide (PAM), has been used in agriculture for its ability to increase infiltration and reduce irrigation-induced erosion. Now, researchers are exploring its potential in stabilizing pavement materials.

The PAM Promise: How It Works

Futuristic road construction with polymer additive.

A recent study investigated the use of a synthetic polyacrylamide-based additive (PAM) to stabilize three types of soil commonly used in unsealed pavement construction. The study, conducted by Romel N. Georgees and Rayya A. Hassan, focused on evaluating the performance of soils treated with PAM through Unconfined Compressive Strength, California Bearing Ratio, and erosion tests. The results revealed a significant overall increase in strength for all soil types, with varying degrees of improvement. The treated soils also exhibited enhanced bearing capacity and erosion resistance, suggesting PAM could be a game-changer for road construction.

The researchers tested three different soil types (A, B, and C) sourced from various sites in Australia, representative of in-situ stabilization projects. The polymeric additive used was a synthetic soluble anionic polyacrylamide (PAM) in granular form, characterized by a charge density of approximately 18% and a high molecular weight (12–15 Mg/mol). Physical characterization tests, including plasticity limit, liquid limit, and particle size distribution, were performed according to Australian Standards to classify the soils using the Unified Soil Classification System (USCS).

The key benefits of PAM in soil stabilization include:

Reduced Permeability: PAM helps to create a tighter soil matrix, reducing the amount of water that can penetrate the road base.
Increased Durability: By binding soil particles together, PAM enhances the overall strength and resilience of the pavement.
Improved Erosion Resistance: PAM-treated soils are less susceptible to erosion from rainfall and water flow, prolonging the life of the road.
Enhanced Bearing Capacity: The California Bearing Ratio (CBR) tests showed improvements in the load-bearing capacity of soils treated with PAM.

The study's findings suggest that PAM enhances soil properties by creating a more cohesive and resilient structure. In wet conditions, PAM-treated samples exhibited dramatically higher retained strength compared to untreated samples. For example, soil type B showed a 146.6% increase in strength when treated with PAM, indicating significant resistance to moisture deterioration. This is particularly important for soils with higher porosity and water absorption. It is believed that the polymer effectively seals the soil's pores, preventing water from permeating and preserving the dry strength of the pavement material.

The Road Ahead: A Sustainable Future

The research indicates that PAM is a promising stabilizing additive for improving the performance of pavement foundation materials sustainably. Its use could reduce pavement thickness, which is particularly valuable when rehabilitating urban pavements to match existing infrastructure levels. The increased strength will provide a tougher structural layer that mitigates the stresses imposed on the foundation by construction traffic. Further, the improved durability and resistance to erosion of treated material helps to reduce mass loss due to the erosion action of rainfall during the construction of the foundation unbound layers and facilitate staged construction to reduce traffic delay in the urban environment.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/978-3-030-01917-4_8, Alternate LINK

Title: Stabilization Of Subgrade Soil Using Polyacrylamide-Based Additive

Journal: Sustainable Civil Infrastructures

Publisher: Springer International Publishing

Authors: Romel N. Georgees, Rayya A. Hassan

Published: 2018-10-28

Everything You Need To Know

How does polyacrylamide (PAM) enhance soil properties for road construction?

Polyacrylamide (PAM) works by creating a tighter soil matrix, which reduces water permeability into the road base. This increased binding of soil particles enhances the overall strength and resilience of the pavement. PAM-treated soils are also more resistant to erosion from rainfall and water flow. The California Bearing Ratio (CBR) tests confirm that it improves the load-bearing capacity of soils.

What are the advantages of using polymers like polyacrylamide (PAM) compared to traditional cementitious additives in road stabilization?

Traditional stabilization methods use cementitious additives to enhance pavement performance. However, these require large quantities of additives and lengthy curing times, leading to increased construction time and costs. Also, cementitious additives can increase the risk of reflective cracking in asphalt surfaces. Polyacrylamide (PAM) offers advantages such as reduced permeability, increased durability, improved erosion resistance, and enhanced bearing capacity while also being less time-dependent and more environmentally sustainable.

What specific type of polyacrylamide (PAM) was used in the study, and who conducted the research?

The study used a synthetic soluble anionic polyacrylamide (PAM) in granular form. This particular PAM had a charge density of approximately 18% and a high molecular weight (12–15 Mg/mol). The researchers, Romel N. Georgees and Rayya A. Hassan, tested this PAM on three different soil types (A, B, and C) sourced from various sites in Australia.

Why is reduced permeability important in pavement foundation materials, and how does polyacrylamide (PAM) contribute to this?

The reduced permeability achieved by using polyacrylamide (PAM) in soil stabilization helps to prevent water from penetrating the road base, preserving the dry strength of the pavement material. This is particularly important for soils with higher porosity and water absorption, as demonstrated by soil type B's 146.6% increase in strength when treated with PAM in wet conditions. This retained strength is vital for maintaining the structural integrity and longevity of roads, especially in regions with significant rainfall or fluctuating moisture levels.

What are the broader implications of using polyacrylamide (PAM) in road construction for sustainable infrastructure?

Using polyacrylamide (PAM) as a stabilizing additive can lead to more sustainable road construction by allowing for reduced pavement thickness, particularly valuable in urban rehabilitation. The increased strength of PAM-treated soil provides a tougher structural layer, mitigating stresses from construction traffic. Moreover, the improved durability and erosion resistance reduce material loss during construction and facilitate staged construction, which reduces traffic delays in urban areas. While the study highlights PAM's benefits, further research into its long-term environmental impact and optimal application techniques is necessary to fully realize its potential for sustainable infrastructure.