Written by Morgan Kaenzig de Denus, AMAST Content

Photo from civilengi.com

It is no surprise that a third of all municipal waste in the United States consists of paper, given that the average American uses more than 680 pounds of paper products annually. Since the start of human civilization, the global tree population has fallen by 46%, and an average of 15 billion trees are cut down per year, with 35% of those 15 billion trees used by the paper industries. Instead of sending paper waste to the landfill, it can be recycled and used in papercrete.

What Is Papercrete?

Papercrete consists of a mixture of re-pulped paper and Portland cement. There is no standardized papercrete mixture, and some mixtures include clay, soil, or sand. The paper fiber can come from anything, including old newspapers to used phone books to junk mail to old printer paper. Some papercrete mixtures even include cardboard.

Papercrete was first patented in the 1920s, but it still has not gained mainstream popularity. This is in part because there is no standardized papercrete mixture. Papercrete is considered an alternative material, so it falls under ICC Codebook section 104.11 along with straw bale and adobe. Due to its status as an alternative material, papercrete is approved on a case-by-case basis.

What Are the Benefits of Using Papercrete?

Inexpensive & Available
Papercrete’s raw materials are relatively inexpensive and available. The paper products can be locally sourced, and Portland cement — the most common type of cement — is composed of readily available materials like shale and limestone. The equipment necessary for making papercrete is also relatively cheap. As a result, papercrete is an excellent option for those on a budget.

Environmentally Friendly
Since papercrete uses repulped paper, you can rest assured that you are not continuing to contribute to the 15 billion trees that are cut down each year. At the end of its lifetime, papercrete can be recycled and made into new papercrete, adding another level of sustainability.

Insulation
Papercrete is also an excellent insulator. It will generally have an R-value of 2.8 per inch, so using papercrete will reduce the amount of heating needed in the winter and cooling needed in the summer, resulting in less energy consumption.

Easy & Flexible Installation
Papercrete can be formed into blocks, panels, or sheets, allowing for easy installation in a variety of situations. Papercrete can be used in many of the same situations that concrete can, but it is much lighter, making construction easier.

Strength
Despite its lighter weight, papercrete is still quite strong. It can hold its shape when wet and has a compressive strength of 260 psi. Papercrete also has high tensile strength, thanks to the paper fibers’ presence.

What Are the Limitations?

Water
Papercrete is not waterproof, though it becomes more impervious to water when sand and other minerals are added to the mixture. With a protective coating, papercrete will be more impervious to water. However, if any water penetrates the coating, mold may start to grow.

Shrinkage & Slow Drying
Unfortunately, papercrete has been known to shrink. Adding more sand to the mixture can minimize shrinkage while also making the papercrete more fire resistant and abrasion resistant.

Papercrete also takes a long time to dry. To speed up papercrete’s dry time, let it air dry and try to work on long and warm days.

What’s Next for Papercrete?

While it is not yet widely used in construction projects, papercrete may become more popular in the coming years as people continue to discover how useful and sustainable it is. In the future new standards for papercrete’s materials and strength may also be introduced.

Sources

Building — Building with Papercrete — 2002.113. ArchitectureWeek. (n.d.). Retrieved May 27, 2021, from http://www.architectureweek.com/2002/1113/building_1-1.html.

Dille, I. (2019, April 20). Imagine There’s No Concrete: Building a Papercrete Revolutini in Mason. The Texas Observer. Retrieved May 27, 2021, from https://www.texasobserver.org/imagine-theres-no-concrete-building-a-papercrete-revolution-in-mason/.

The Truth about Papercrete. (n.d.). Retrieved May 27, 2021, from http://www.greenhomebuilding.com/articles/papercrete.htm.

What is Papercrete? Rise. (2020, November 4). Retrieved May 28, 2021, from https://www.buildwithrise.com/stories/what_is_papercrete.

What is Papercrete? Its Properties, Uses and Benefits in Construction — Concrete Technology. The Constructor. (2017, November 11). Retrieved May 28, 2021, from https://theconstructor.org/concrete/papercrete/1961/.

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