you could fill it w/epoxy but w/o addressing the crack's cause, it'll just crk along an adjacent parallel axis,,, i suspect its crack'd because there was no control jnt therefore this crk's become a ' working jnt ' & should be treat'd as such despite the appearance,,, the proper method is to create a sealant reservoir of the proper size & shape factor for the sealant you choose,,, i'd suggest 100% silicone OR sika's ' sl2 ',,, ( sl2 comes in colors but only 1 color at any apron store ),,, read the label/website for more inf - good luck !
hesitate to post the pro's repair as 1 out of 1,000 h/o's invest the $.
