The most common and most likely answer to this crossword clue is the 8 letter word PHYSICAL
I've seen this crossword clue in Independent
P
H
Y
S
I
C
A
L
More clues leading to the result PHYSICAL
- Concrete is child’s play to mix, vacuous lad conceded
- Materialistic, like some jerks
- Carnal lay with chips scattered all over the place
- Non-intellectual sort of exercise in the school curriculum
- Examination material
- Material Chekhov initially included in his play rewritten
- Centre-forward initially lay with hips broken — check for fitness
- Blow hot and cold play is sensual
- Concrete chips lay all over the place
- Wicked Caliphs incarcerate Yankee corporal
Buddy explains!

The straight part
We know that "Concrete" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case concrete = physical.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PHYSICAL mean?
PHYSICAL noun- Physical examination.
- Of medicine.
- Of matter or nature.
- Of the human body.