This collection contains 37 papers presented at the Eleventh International Conference on Superplasticizers and Other Chemical Admixtures in Concrete in Ottawa, Canada. in July 2015. Topics include; Effect of Clinker Grinding Aids on Static Yield Stress of Cement Pastes; New Additive to Enhance the Slump Retention; Mastering Flow Loss in Superplasticized Cementitious Systems; and much more.