Details Of Technical Competence

 

1) HIGH PERFORMANCE CEMENT

a. INTRODUCTION

 

HPC 62.5R is a high performance and early high strength cement that has been produced with a special grinding method using complex chemical & mineral admixture with clinker and gypsum. HPC 62.5R cement is based on low water demand binder technology, reducing water demand of cement and consequently raising the early compressive strength and overall performance. In numerous lab tests it has been proved that strength values around 100 MPa could be reached very easily. On the other hand, HPC 62.5 due to its non-shrinking features is very suitable for special applications like grouting and joint filers. The mortars produced with HPC 62.5R provide impermeability and excellent freezing and thawing resistance. While it could be used in the field which requires such features, it is very advantageous in precast applications since it shortens demolding time as a result of early strength development in ambient temperatures.

b. COMPOSITION, CHEMICAL AND PHYSICAL PROPERTIES

 

The HPC 62.5 Technology is based on activation of Portland clinker by means of chemical any physical procedures in a special grinding process. Its content by weight is as follows (TABLE1):

TABLE – 1

 

HPC 62.5R content by weight

Clinker C3S>60	Gypsum	Admixtures
%94	%5	%1

 

MORTAR & CONCRETE STRENGTH

 

The test results of strength development of HPC 62.5 and PC 42.5 cements are summarized as follows in graph1 (TABLE 2):

TABLE – 2

 

Compressive strength values

Description	2 Days	7 Days	28 Days
HPC 62.5R	33	56	73
PC 42.5	21	37	54

 

These test figures are the results of lab experiments based on 44% w/c, which is found as the best ratio. In the flow table test 185-190 mm consistence is suitable.

On the other hand, tests aimed to measure early age compressive strength values, made with concrete samples of HPC 62.5R and PC 42.5 having same mix design and 360kg/m³ dosage, have shown that the mixes with HPC 62.5R have much higher compressive strength values. Further increase of these values is also possible using a special concrete admixtures.(Graph2,

TABLE – 3

 

Early ages compressive strength values

Description	12 Hours	18 Hours	24 Hours
HPC 62.5RA*	6	12	18
HPC 62.5R	5	11	17
PC 42.5	3	6	7

 

* HPC 62.5RA with special concrete admixture

These test results allow HPC 62.5R to be classified as a rapid hardening cement beside its long term strength and durability.

c. COMPATIBILITY

 

Like other Ordinary Portland cements HPC 62.5R is compatible with all normal building materials. Due to its adherence and impermeability, HPC 62.5R will prevent corrosion of reinforcing steel and it will not have harmful effect on any other part of structure with which it comes in contact.

d. APPLICATION

 

While using HPC 62.5R in concrete, w/c should be less than 45 % and there should be no concrete admixtures. During winter time antifreeze agents can be used. HPC 62.5R has build in characteristics which improves workability, early and final compressive strengths, reduces shrinkage and permeability of concrete. Therefore, no other admixtures are needed in order to give these properties to concrete and mortars. This feature not only prevents possible operator’s dosage mistakes but also allows time saving due to additional admixture applications. In order to obtain high strength, mix designs with 30-40% w/c ratios which give 80-120 mm slump are advised.

e. CONCRETE PROPERTIES

 

Early strength up to 30 MPa in 24 hours and 50 MPa in 48 hours. High compressive strength up to 120 MPa in 28 days.

Durability of structures as a result of higher performance. Early demolding generally without steam curing application.

High workability and ability to fill moulds with complicated shapes. High resistance to abrasion.

High adherence and impermeability.

2. POLYMIX READY PLASTER

a. INTRODUCTION

 

Polymix® and Polymix® MS Ready Plasters are ready to application lime – free mortars produced in accordance with technology of ISOLA BAUCHEMIE GmbH (Germany).

Polymix® requires no additional mixing on construction site. Due to use of special retarding admixtures it will remain completely usable for the specified period of 48 hours. Polymix® is consistent in composition, strength, workability and color.

b. COMPOSITION

 

Polymix® Ready Plaster is composed of cement, fine and coarse natural sands together with specially selected polymer admixtures, surface-active air entraining and retarding agents. Polymix® MS Ready Plaster in addition contains high reactive micro silica.

TABLE – 1

Nominal Proportions by Weight
Products	Cement	Micro silica	Find Sand	Coarse Sand	Admixtures % Cement
Polymix®	1	–	1,4	2,7	1
Polymix® MS	1	0,1	1,4	2,7	1