Semirigidity assessment of reinforced concrete beam column joint designed to withstand seismic force from SNI 1728 2012 and SNI 1728 2002 seismic code in accordance to Indonesian structural concrete code = Kajian semikaku sambungan balok-kolom beton bertulang yang dirancang untuk menahan beban gempa dari peraturan gempa SNI 1728:2012 dan SNI 1728:2002 menurut peraturan beton struktural Indonesia