So, you can try this solution:
DECLARE @DAY INT = 25
DECLARE @MONTH INT = 10
DECLARE @YEAR INT = 2016
DECLARE @DATE AS DATETIME
SET @DATE = CAST(RTRIM(@YEAR * 10000 + @MONTH * 100 + @DAY) AS DATETIME)
SELECT REPLACE(CONVERT(VARCHAR(10), @DATE, 102), '.', '-') AS EXPECTDATE
Or you can try this a few lines of code:
DECLARE @DAY INT = 25
DECLARE @MONTH INT = 10
DECLARE @YEAR INT = 2016
SELECT CAST(RTRIM(@YEAR * 10000 +'-' + @MONTH * 100+ '-' + @DAY) AS DATE) AS EXPECTDATE