PokerStars No-Limit Hold'em, $0.10 BB (5 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP ($10)
Button ($20)
SB ($10.30)
BB ($10.80)
Hero ($11.20)

Preflop: Hero is UTG with J, A. MP posts a blind of $0.10.
Hero raises to $0.5, 1 fold, Button calls $0.50, 2 folds.

Flop: ($1.25) Q, A, 5 (2 players)
Hero bets $0.8, Button calls $0.80.

Turn: ($2.85) 2 (2 players)
Hero bets $1.8, Button calls $1.80.

River: ($6.45) T (2 players)
Hero bets $3, Button folds.

Final Pot: $6.45

Just trying to get to grips with the concept of blocking bets, and when the right time to make them is.

Villain is 50/21/1.87 over 58 hands. My notes on him read as follows - "can slow play a big made hand. can make a big river float. reraises with AT. can make a rich bluff when he's already put a lot in."

It's only a small sample, but me and villain have tangled quite a lot since I sat down. He seems to be playing "backwards" a lot, i.e checking the nuts and betting Queen high. He's not a complete wild man, but he's not far off. His passivity is characteristic of the few times when he's either had something massive, or is chasing. On the other hand, I've only seen him play 58 hands, so this is hardly a tight read. I elected to put in a half PSB as blocking bet against his likely bluff, and to extract some value from weaker aces (since I'm fairly sure he would've reraised AT+).

Am I using the blocking bet correctly here? Should I have just gone for it and PSB'd? Is this a check/fold what with the club/T? Or maybe because he's so lagg I can check-raise him and feel good about it? Is it a check/call?

I'm mainly concerned with whether I have the right idea about blocking bets here.