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）由于降低水/水泥比而导致可加工性改善和强度增加。作为缺点，由于这些超塑化剂与水泥化合物的相互作用，导致强度发展延迟。该应用旨在调查这种水泥水化延迟的原因以及将液化与不延迟相结合的某种聚合物结构的可能性。根据水泥熟料纯相C_3S的溶解和不同结构的高效减水剂对水泥水化相纯结晶的影响结果，认为应通过改性体系来加速水泥水化。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，聚合物在C-S-H相中的插层是该项目第三部分的主要课题。为了研究这种插层是否能同时改善水泥石的力学（主要是抗拉强度）和应变（主要是蠕变）性能，该应用将继续一年的基金项目（LU 1652/1-2），该项目旨在将水化部分分为溶解和结晶两部分，这两部分都受到高效减水剂的影响。特别注意的是反应动力学。在第一次成型过程中，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，不同有机添加剂的影响将延长溶解过程。对水化产物为水化硅酸钙（C-S-H）相、钙钛矿和钙矾石的均相结晶实验进行了研究。在这些研究中，超塑化剂结构（侧链长度，官能团量等）的影响。对结晶速率的影响。第三点是研究了有机聚合物作为水泥的初始相插入C-S-H晶面引起的水泥强度。通过适应生物矿化的原理，预期材料的性能会有所提高。本课题是水泥研究的一个新领域，将在该领域产生重大影响。此外，水化机制和新材料性能的基本原理的详细知识旨在对材料科学（地质学，仿生学）进行跨学科讨论。

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).