The total cost for the sand is 500*10 = $<<500*10=5000>>5000
Since each lorry was carrying 10 tons of sand, the twenty lorries carried 20*10 = <<20*10=200>>200 tons.
At $40 per ton, Mr. Zander paid 200*$40 = $<<200*40=8000>>8000 for the sand that was delivered to his construction site.
Altogether, Mr. Zander paid $8000+$5000 = $<<8000+5000=13000>>13000 for the delivered construction materials.
#### 13000