Concrete
Cement vs Concrete: What's the Difference?
Cement is an ingredient. Concrete is the finished material. Here is the difference.
Read ›Materials science, in plain English
How the materials around you actually work
Concrete, reinforcing steel, composites, and polymers, explained from the science up: how they are made, why they fail, and what the numbers on the bag or the drawing mean.
70-80%
of concrete is aggregate
28 days
to design strength
1/2 in
diameter of #4 rebar
~1/4
GFRP weight vs steel
Three fields, one idea
What we cover
Concrete
Concrete
What it is made of, how it cures and cracks, and what psi and mix ratios really mean.
ReinforcementReinforcement
Rebar sizes and grades, why concrete needs steel, and where composite bars beat it.
PolymersPolymers
Polyurethane and the resins behind coatings, foams, sealants, and composite rebar.
Start here
Featured guides
Reinforcement
Rebar Sizes Explained
The number is the diameter in eighths of an inch. Full size chart and grades.
Read ›Polymers
Is Polyurethane Toxic?
Cured, it is inert. Wet and curing, it needs air. The safety facts.
Read ›All guides
The reference library
Concrete
Cement vs Concrete: What's the Difference?
Cement is an ingredient. Concrete is the finished material. Here is the difference.
Concrete
How Long Does Concrete Take to Cure?
24 hours to walk, 7 days to drive, 28 days to full strength, and why.
Concrete
Concrete PSI Explained
What compressive strength means, and which psi suits which job.
Concrete
Concrete Mix Ratio: The 1-2-3 Rule
1 cement, 2 sand, 3 gravel, and why water is the ingredient that decides strength.
Concrete
Why Concrete Cracks
Shrinkage, settlement, and rust, and which cracks are cosmetic vs structural.
Concrete
What Is Efflorescence on Concrete?
The white powder is salt left by evaporating water. Causes, and how to remove it.
Reinforcement
Rebar Sizes Explained
The number is the diameter in eighths of an inch. Full size chart and grades.
Reinforcement
Fiberglass Rebar vs Steel (GFRP)
The composite bar that never rusts: where GFRP beats steel, and where it does not.
Polymers
Is Polyurethane Toxic?
Cured, it is inert. Wet and curing, it needs air. The safety facts.
Reinforcement
What Is Rebar?
The steel bar that carries the tension concrete cannot.
Reinforcement
Rebar Spacing for a Concrete Slab
How to read a spacing callout, what cover does, and who decides the number.
Concrete
Types of Cement Explained
Four portland types, one retired type, and the blended cements that replaced it.
Polymers
Epoxy vs Polyurethane
One is hard and bonds; the other flexes and survives sunlight.
Polymers
Open Cell vs Closed Cell Spray Foam
Gas-filled and rigid, or air-filled and spongy. The trade is R-value against cost.
About this project
An independent, plain-language materials desk
Materials Review is an independent educational resource. We read the primary literature, from university materials-science modules to ASTM and ACI standards, and translate it into clear explanations for builders, students, and curious homeowners. We cite our sources and we are not affiliated with any university or trade body.