Influence of PCE-superplasticizer on the nucleation and growth of products obtained during the hydration of portland cement and the intercalation of polymers in C-S-H phases.

在混凝土和砂浆生产中，使用聚羧酸盐基聚合物（高效减水剂）可以改善和易性，并通过降低水灰比提高强度。作为一个缺点，由于这些高效减水剂与水泥化合物的相互作用，导致强度发展迟缓。该应用程序旨在研究水泥水化延迟的原因，以及某种聚合物结构结合液化与无延迟的可能性。根据纯熟料相C3S的溶解和不同结构的高效减水剂影响下胶凝水相的纯结晶结果，可以通过对体系进行改性来加速水泥的水化。因此，可以获得聚合物诱导的加速度。除了聚合物影响水泥水化的动力学研究外，项目第三部分的主要课题是聚合物在C-S-H相的插层。研究这种嵌入是否会改善水泥石的力学性能（主要是抗拉强度）和应变性能（主要是蠕变）。该申请将继续进行为期一年的项目（LU 1652/1-2），该项目旨在将水化部分分离为受高效减水剂影响的溶解和结晶。特别注意了反应动力学。在第一次建立过程中，证明了所用方法的适用性，这些方法可用于溶解和结晶实验。不同有机添加剂的加入会延长溶解过程。将对水合硅酸钙（C-S-H）相、波特兰铁矿和钙矾石作为主要水合产物进行均匀结晶实验。在这些研究中，研究了高效减水剂的结构（侧链长度、官能团数量等）对结晶速率的影响。第三点研究了有机聚合物作为源相在C-S-H相晶面上的插层作用对水泥强度的影响。通过适应生物矿化原理，期望提高材料的性能。本课题是水泥研究的一个新领域，必将引起水泥研究领域的重大进展。此外，详细了解水化机制的基本原理和新材料的性质，旨在材料科学（地质学，仿生学）的跨学科讨论。

In concrete and mortar production the use of polycarboxylate based polymers (superplasticizer) leads to improved workability and increased strenght due to reduced water/cement ratios. As a drawback the strength development is retarded caused by the interaction of these superplasticizer with cement compounds. The application is aimed to investigate the causes of this retardation of the cement hydration and the possibility for a certain polymer architecture combining the liquefaction with no retardation. Based on the results obtained from the dissolution of the pure clinker phase C3S and from the pure crystallization of cementitious hydrous phases influenced by superplasticizer different in their structure, the cement hydration should be accelerated by modification of the system. Thus a polymer induced acceleration is obtainable. Besides kinetic studies dedicated to the hydration of cements influenced by polymers the intercalation of polymers in C-S-H phases is main topic in the 3rd part of the project. It is to investigate if such intercalation will improve both mechanic (mainly tensile strength) and strain (mainly creeping) properties of the cement stone.The application will continue the one year fonded project (LU 1652/1-2) which is aimed to separate the hydration parts into dissolution and crystallization both influenced by superplasticizers. Special attention is paid on the reaction kinetics. During the first fonding the suitability of used methods was proved and these methods can be used for the dissolution and crystallization experiments.The dissolution process will be extended by the influence of different organic additives. Homogeneous crystallization experiments will be performed on calcium-silicate-hydrate (C-S-H) phases, portlandite as well as ettringite as main hydration products. In these investigations the influence of the superplasticizer structure (side chain length, amount of functional groups, etc.) on the crystallization rate is investigated. The third point is the intercalation of organic polymers into the crystal planes of C-S-H phases as origin phase causing the strength in cement is investigated. By adaption of principles of biomineralization an increased performance of the material is expected. This topic is a new field for the research on cements and will lead to a significant effort in the field. Furthermore detailed knowledge of basic principles of the hydration mechanisms and new materials properties are aimed for interdisciplinary discussion on materials sciences (geology, bionic).