SURP 2025: BIOLOGICAL STAKBLOCKS

WHAT IS OUR PROJECT?

In many communities around the world, agricultural waste exists as an unsolved problem. The goal of our project is using high pressure while heating this agricultural waste, we can turn it into a carbon-negative building material. In collaboration with CalPoly staff members and Stakblock.com, we are developing a procedure that enables our global collaborators to produce this building material easily and reliably.

Some general steps forward for this project are as follows.

Reliably produce a product with a pressure/temperature ratio with the desired density.
Design and/or produce the desired shape of the product, making any changes to the previous step if needed
Materials testing of said product

We currently have reliable test samples that we will take forward to material testing.

PROCEDURE

Using a Carver Laboratory Press Model M in combination with a specially machined device consisting of a square metal pipe, surrounded by four PTC heaters and insulation held within an outer metal shell, with a thermal couple slid into the bottom of the device into the space between the heater and the insulation. A wood block with an aluminum slab on top is positioned at the bottom of the device, sandwiched between cardboard and brick to keep the material thermally insulated and reduce material creep.

From here, we have been testing two different methodologies to see if an order matters. Method 1: Insert filler material, compress, and then heat to 140 °C while maintaining compression as necessary for a maximum of one hour. Method 2: Heat to 140 °C, insert filler material, then compress.

Compressing is achieved by attaching a known weight to the press lever and raising it until it can no longer fall under its own weight. Occasionally, we tap the lever without applying excessive force.

To the left is our experimental setup used in our lab at CalPoly SLO

With Method 1, we are generally able to achieve an average FOC (factor of compression) of 2.57 and an average density increase of 440.7%, with an overall operating time longer than Method 2.

With Method 2, we are generally able to achieve an average FOC of 3.2 and an average density increase of 219.87%. With an overall operating time shorter than Method 11

Many factors contribute to these numbers. For instance, the amount of material used in the first two trials of Method 1 is significantly lower than in the later trials of Method 2, primarily due to the operator's increased skill. Nevertheless, we still observe a general increase in density with Method 1. However, Method 1 takes longer than Method 2 to produce a singular sample

RESULTS: METHOD 1

To the left are the afformentioned samples. All data for each can be seen in the Important Files tab but from left to right we have samples 12, 13, and 15.

Final Weight: 56g

Final Weight: 100g

Final Weight: 144g

RESULTS: METHOD 2

Final Weight: 70g

Final Weight: 95g

Final Weight: 106g

Page updated

Google Sites

Report abuse