Kai asked about it in Blood Legacy when the updated Yen-Lo-Wang was revealed to him. he was told that you could hypothetically do it, but that "the average I-beam has terrible ballistic qualities"
Kai later in Lost Destiny used that same guass rifle, salvaged off his submerged mech and attached to a truckbed, to fire an I-beam in order to blow open a door to a Comstar prison camp, in order to let a point of Elementals (along with himself) into the camp to rescue captured IS and Clan prisoners.