id	keyword
american_scientific_journal-1081	asphalt
american_scientific_journal-1081	rubber
american_scientific_journal-1081	test
american_scientific_journal-1081	mixes
american_scientific_journal-1081	crumb
american_scientific_journal-1081	mixtures
american_scientific_journal-1081	materials
american_scientific_journal-1081	research
american_scientific_journal-1081	fatigue
american_scientific_journal-1081	engineering