You can merge the files with copy /b *.ts output-file.ts as mozzbozz suggest.
However, keep in mind if the filenames are not using leading zeros (1.ts, 2.ts ... 9.ts, 10.ts ... 99.ts, 100.ts ...), the copy command will use alphabetic lexical order to concatenate the files resulting in wrong order and output-file.ts will be glitching back and forth (1.ts, 10.ts, 100.ts, 2.ts, 20.ts, ... 9.ts ... 99.ts, 999.ts).
Filename alphabetical lexical order must match the natural order of video clips. This is fixed by using leading zeros:
for %i in (?.ts) do ren %i 000%i
for %i in (??.ts) do ren %i 00%i
for %i in (???.ts) do ren %i 0%i
copy /b ????.ts output-file.ts